Question

The tangent line to the graph of f(x) = x^2 at the point (x, y) has slope = 2x.

The equation of the tangent line to the graph of f(x) = x^2 at x = -2 is
y =?

Answer 1

y=-4x

Answer 2

slope is -4

Answer 3

the slope is -4 right ,but y=-4x?

Answer 4

because f(-2) = -4 right?

Answer 5

is that correct 14yamaka?

Answer 6

can you show me how you got that,
yamaka?

Answer 7

sry, just got back XD ok

Answer 8

I meant slope is four. This is how we get to the answer:
FIrst, plug x=-2 in as that is the point where the line and the f(x)=x^2 cross.
f(-2)=(x)^2
f(-2)=4
(-2, 4)
Now, we also know that slope is 2x.
THerefore, slope is -4.
So,
y=-4x+b
4=-4(-2)+b
b=-4
y=-4x-4