-20
Given the function f(x) = 2x^4 + 6x^2 + 4 at x = 1, the slope of the tangent of the function is expressed as:
[tex]f^{\prime}(x)=8x^3+12x[/tex]Substitute the value of x = -1 into the fucntion
[tex]\begin{gathered} f^{\prime}(-1)=8(-1)^3+12(-1) \\ f^{\prime}(-1)=8(-1)-12 \\ f^{\prime}(-1)=-8-12 \\ f^{\prime}(-1)=-20 \end{gathered}[/tex]Hence the slope of the tangent to the function at x = -1 is -20
