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About LinkBacksShow that the tangent to P: y= ax^2+bx+c with gradient m has y intercept c-(m-b)^2/4a. thank you.
m = 2ax + b => x = ....Originally Posted by slaypullingcat
Substitute that expression for x into y= ax^2+bx+c to get an expression for y. Now you know a point (x1, y1) on the tangent.
Then the tangent is y - y1 = m(x - x1).
Now substitute x = 0 and solve for y.
Hello, slaypullingcat!
The procedure is simple, but there's a LOT of algebra!
I was lucky to get the answer on the first try . . .
Show that the tangent to: .with gradient
. . has y-intercept: .^2}{4a})
The derivative of: .
If the gradient is
Substitute into [1]: .
The tangent has point. and slope
Its equation is: .
. .
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