calculus-answer check

posted by Kim

Determine the slope of the tangent line to the curve y=(x^2+3x)(x^2-2) at x=-1.

I got 3 as my answer although I am not too sure that it's correct. I found the derivative of the function and then substituted -1 into the equation.

  1. Steve

    that's the proper method.

    Using the product rule,
    y' = (2x+3)(x^2-2) + (x^2+3x)(2x)
    at x=-1, that's (-2+3)(1-2)+(1-3)(-2) = 3

  2. MathMate

    I do not have the same value as yours.
    Can you post the derivative?

  3. MathMate

    Oh, sorry, I had the two terms divided and not multiplied.

  4. Kim


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