
William W. answered 06/14/21
Experienced Tutor and Retired Engineer
The slope of the tangent line to a function can be found by taking the derivative of that function.
For y = -5 - 4x2, the derivative (y') is found using the power rule:
y' = -8x
For the point (-3, -41), x = -3 so the slope is -8(-3) = 24
You can now use the point-slope form of a line y - y1 = m(x - x1) where (x1, y1) is (-3, -41) and m = 24:
y - -41 = 24(x - -3)
y + 41 = 24(x + 3)
If you'd like, you can leave it like this or put it into the slope-intercept form:
y = 24x +31