Find the intervals on which each of the following functions is (a) increasing (b) decreasing.
f(x)=2x3+9x2+12x+15
f’(x)=6x2+18x+12
f’(x)=6(x2+3x+2)
=6(x+2)(x+1)
Function f(x) is decreasing for x ∈ [-1,-2] and increasing in x ∈ (-∞,-1) ∪ (-2, ∞)
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Find the intervals on which each of the following functions is (a) increasing (b) decreasing.
f(x)=2x3+9x2+12x+15
f’(x)=6x2+18x+12
f’(x)=6(x2+3x+2)
=6(x+2)(x+1)
Function f(x) is decreasing for x ∈ [-1,-2] and increasing in x ∈ (-∞,-1) ∪ (-2, ∞)