first you want to find h ' (x)
h ' (x) = cosh(x^2 - 4) + 2x^2*sinh(x^2 - 4)
then you can find h '' (x)
h '' (x) = 6x sinh(x^2 - 4) + 4x^3 * cosh(x^2 - 4)
then plug in x = 2
h '' (2) = 6(2) sinh(2^2 - 4) + 4(2)^3 * cosh(2^2 - 4)
h '' (2) = 12 sinh(4 - 4) + 4(8)cosh(4 - 4)
h '' (2) = 12 sinh(0) + 32 cosh(0)
h '' (2) = 12(0) + 32(1) = 32
so the end value for this scenario should be h '' (2) = 32