Q. - Let f be a function such that f(−1)=3 and f′(−1)=5.- Let g be the function g(x)=2x3.Let F be a function defined as F(x)=g(x)f(x).F′(−1)=
Apply Quotient Rule: To find F′(−1), we need to use the quotient rule for differentiation, which states that if F(x)=g(x)f(x), then F′(x)=(g(x))2f′(x)g(x)−f(x)g′(x). We are given f(−1)=3 and f′(−1)=5. We also have g(x)=2x3, so we need to find g(−1) and g′(−1).
Find g(−1): First, let's find g(−1) by substituting −1 into g(x): g(−1)=2(−1)3 g(−1)=2(−1) g(−1)=−2
Find g′(−1): Next, we need to find g′(−1). To do this, we first differentiate g(x) with respect to x: g′(x)=dxd[2x3] g′(x)=2⋅3x3−1 g′(x)=6x2 Now we substitute −1 into g′(x) to find g′(−1): g′(−1)0 g′(−1)1 g′(−1)2
Apply Quotient Rule: Now we have all the values we need to apply the quotient rule:F′(−1)=(g(−1))2f′(−1)g(−1)−f(−1)g′(−1)F′(−1)=(−2)2(5⋅−2−3⋅6)
Simplify Numerator and Denominator: Let's simplify the numerator and the denominator separately:Numerator: 5×−2−3×6=−10−18=−28Denominator: (−2)2=4
Find F′(−1): Now we can find F′(−1):F′(−1)=4−28F′(−1)=−7