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I added the concept-motivation tag; I also altered the title from "Why should I..." to "Should I..." to make it slightly more neutral. (Admittedly, the latter effect is probably diminishingly small.) Also, I changed 'advanced algebra' to 'high school algebra' to avoid post-secondary confusion.
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Benjamin Dickman
Benjamin Dickman
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Why should Should I be teaching point-slope formula to advancedhigh school algebra students?

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Wmol
Wmol
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I'm student teaching this semester, and so far I'm loving it! Our next section in the book teaches point-slope formula, and my cooperating teacher (a 24-year veteran teacher) is convinced that point-slope formula serves no purpose. He said he has been at a constant "battle" with the other teachers at the high school because there is no purpose. At first, I challenged him, and asked, "what if you have a point far off from the origin?".

Well, the question would provide you with a point and a slope. He said you can just plug those into slope-intercept form (which he loves) and solve for b (the y-intercept). I did some googling and found that the point-slope form reappears in Calc 2 and Calc 3 with polynomials and linear approximation functions. When I showed that to him, he said, "well by the time they get there, they'll just learn it new". So he's STILL not convinced that we should be teaching point-slope formula to these students!

I even challenged him by asking, "isn't it important for these students to see multiple ways to write equations for lines?". No, slope-intercept is all they need to get through the class. "Well, if you're given a point and a slope (say x1,y1 and m), you could plug them into the equation to get y-y1=m(x-x1) and type that straight into desmos and get a line without having to do any work". Well, my technology argument was a no-go as well. So I'm at a loss.

EDIT: After reading a few replies, I showed him how simple it is to derive the point-slope formula from the slope form m=(y2-y1)/(x2-x1), and then from there you could derive the slope-intercept form, but his response was, "or they could just know slope-intercept form and use it every time".

Am I crazy in thinking that point-slope formula is important for these students in 9th grade honors algebra? How can I convince my cooperating teacher?

I'm student teaching this semester, and so far I'm loving it! Our next section in the book teaches point-slope formula, and my cooperating teacher (a 24-year veteran teacher) is convinced that point-slope formula serves no purpose. He said he has been at a constant "battle" with the other teachers at the high school because there is no purpose. At first, I challenged him, and asked, "what if you have a point far off from the origin?".

Well, the question would provide you with a point and a slope. He said you can just plug those into slope-intercept form (which he loves) and solve for b (the y-intercept). I did some googling and found that the point-slope form reappears in Calc 2 and Calc 3 with polynomials and linear approximation functions. When I showed that to him, he said, "well by the time they get there, they'll just learn it new". So he's STILL not convinced that we should be teaching point-slope formula to these students!

I even challenged him by asking, "isn't it important for these students to see multiple ways to write equations for lines?". No. "Well, if you're given a point and a slope (say x1,y1 and m), you could plug them into the equation to get y-y1=m(x-x1) and type that straight into desmos and get a line without having to do any work". Well, my technology argument was a no-go as well. So I'm at a loss.

Am I crazy in thinking that point-slope formula is important for these students in 9th grade honors algebra? How can I convince my cooperating teacher?

I'm student teaching this semester, and so far I'm loving it! Our next section in the book teaches point-slope formula, and my cooperating teacher (a 24-year veteran teacher) is convinced that point-slope formula serves no purpose. He said he has been at a constant "battle" with the other teachers at the high school because there is no purpose. At first, I challenged him, and asked, "what if you have a point far off from the origin?".

Well, the question would provide you with a point and a slope. He said you can just plug those into slope-intercept form (which he loves) and solve for b (the y-intercept). I did some googling and found that the point-slope form reappears in Calc 2 and Calc 3 with polynomials and linear approximation functions. When I showed that to him, he said, "well by the time they get there, they'll just learn it new". So he's STILL not convinced that we should be teaching point-slope formula to these students!

I even challenged him by asking, "isn't it important for these students to see multiple ways to write equations for lines?". No, slope-intercept is all they need to get through the class. "Well, if you're given a point and a slope (say x1,y1 and m), you could plug them into the equation to get y-y1=m(x-x1) and type that straight into desmos and get a line without having to do any work". Well, my technology argument was a no-go as well. So I'm at a loss.

EDIT: After reading a few replies, I showed him how simple it is to derive the point-slope formula from the slope form m=(y2-y1)/(x2-x1), and then from there you could derive the slope-intercept form, but his response was, "or they could just know slope-intercept form and use it every time".

Am I crazy in thinking that point-slope formula is important for these students in 9th grade honors algebra? How can I convince my cooperating teacher?

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Wmol
Wmol
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Why should I be teaching point-slope formula to advanced algebra students?

I'm student teaching this semester, and so far I'm loving it! Our next section in the book teaches point-slope formula, and my cooperating teacher (a 24-year veteran teacher) is convinced that point-slope formula serves no purpose. He said he has been at a constant "battle" with the other teachers at the high school because there is no purpose. At first, I challenged him, and asked, "what if you have a point far off from the origin?".

Well, the question would provide you with a point and a slope. He said you can just plug those into slope-intercept form (which he loves) and solve for b (the y-intercept). I did some googling and found that the point-slope form reappears in Calc 2 and Calc 3 with polynomials and linear approximation functions. When I showed that to him, he said, "well by the time they get there, they'll just learn it new". So he's STILL not convinced that we should be teaching point-slope formula to these students!

I even challenged him by asking, "isn't it important for these students to see multiple ways to write equations for lines?". No. "Well, if you're given a point and a slope (say x1,y1 and m), you could plug them into the equation to get y-y1=m(x-x1) and type that straight into desmos and get a line without having to do any work". Well, my technology argument was a no-go as well. So I'm at a loss.

Am I crazy in thinking that point-slope formula is important for these students in 9th grade honors algebra? How can I convince my cooperating teacher?