Find the equation of the line

Question

Find the equation of the line tangent to y = -3x^2 + x - 5 at x = -1.

1) y = 2x - 2

2) y = 2x + 2

3) y = -7x - 2

4) y = 7x - 2

Answer 1

yPrime = -6x + 1

slope M = fPrime(-1) = 7

f(-1) = -9 , so (-1,-9) is on the line

B = y - mx = -9 - 7 * -1 = -9 - -7 = -2

y = 7x-2

must be option #4 because it is the only line with slope m=7, but there ya go