Q. Given the function f(x)=3x3−41−x, find f′(x) in simplified form.Answer: f′(x)=
Quotient Rule Explanation: To find the derivative of the function f(x)=3x3−41−x, we will use the quotient rule. The quotient rule states that if we have a function that is the quotient of two functions, v(x)u(x), then its derivative f′(x) is given by (v(x))2v(x)u′(x)−u(x)v′(x). Here, u(x)=1−x and v(x)=3x3−4.
Derivative of u(x): First, we need to find the derivative of u(x)=1−x. The derivative of a constant is 0, and the derivative of −x with respect to x is −1. Therefore, u′(x)=0−1=−1.
Derivative of v(x): Next, we need to find the derivative of v(x)=3x3−4. The derivative of 3x3 with respect to x is 9x2, and the derivative of a constant is 0. Therefore, v′(x)=9x2−0=9x2.
Applying Quotient Rule: Now we apply the quotient rule. f′(x)=(v(x))2v(x)u′(x)−u(x)v′(x). Plugging in the derivatives we found, we get f′(x)=(3x3−4)2(3x3−4)(−1)−(1−x)(9x2).
Simplify Numerator: Simplify the numerator of the derivative. f′(x)=(3x3−4)2−3x3+4−9x2+9x2x. Notice that −9x2+9x2x simplifies to −9x2(1−x).
Further Simplify Numerator: Further simplify the numerator. f′(x)=(3x3−4)2−3x3+4−9x2+9x3. Combine like terms in the numerator, which are −3x3 and 9x3.
Combine Like Terms: After combining like terms, we get f′(x)=(3x3−4)26x3+4−9x2. This is the simplified form of the derivative.
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