The derivative of the function f is defined by f′(x)=(x2−4x)sin(3x+2). If f(3)=−6, then use a calculator to find the value of f(−2) to the nearest thousandth.Answer:
Q. The derivative of the function f is defined by f′(x)=(x2−4x)sin(3x+2). If f(3)=−6, then use a calculator to find the value of f(−2) to the nearest thousandth.Answer:
Integrate f′(x): To find f(−2), we need to integrate f′(x) to get f(x) and then use the initial condition f(3)=−6 to find the constant of integration.Integrate f′(x)=(x2−4x)sin(3x+2).This requires integration by parts or a special technique since it is a product of a polynomial and a trigonometric function.
Apply integration by parts: Let's set u=x2−4x and dv=sin(3x+2)dx. Then we need to find du and v.Differentiate u to get du=(2x−4)dx.Integrate dv to get v=−31cos(3x+2).
Simplify and split integral: Apply the integration by parts formula: ∫udv=uv−∫vdu. Substitute u, du, v, and dv into the formula. f(x)=−(x2−4x)(31cos(3x+2))−∫(−31cos(3x+2))(2x−4)dx.
Integrate by parts again: Simplify the integral and split it into two separate integrals. f(x)=−(x2−4x)(31cos(3x+2))+(32)∫(xcos(3x+2))dx−(34)∫cos(3x+2)dx.
Integrate remaining integral: The first integral, ∫(xcos(3x+2))dx, again requires integration by parts. Let's set u=x and dv=cos(3x+2)dx. Differentiate u to get du=dx. Integrate dv to get v=31sin(3x+2).
Combine all parts: Apply the integration by parts formula to the first integral.This gives us (31)xsin(3x+2)−∫(31sin(3x+2))dx.
Simplify and integrate: The remaining integral, ∫sin(3x+2)dx, is straightforward. Integrate to get −31cos(3x+2).
Use initial condition: Combine all parts to express f(x).f(x)=−(x2−4x)(31cos(3x+2))+(32)(31xsin(3x+2)−∫31sin(3x+2)dx)−(34)(−31cos(3x+2)).
Calculate constant of integration: Simplify the expression for f(x) and integrate the remaining term.f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)+(91)cos(3x+2)−(94)cos(3x+2).
Find f(−2): Combine like terms to get the final expression for f(x).f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)−(31)cos(3x+2).
Find f(−2): Combine like terms to get the final expression for f(x). f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)−(31)cos(3x+2).Use the initial condition f(3)=−6 to find the constant of integration C. Substitute x=3 into the expression for f(x) and solve for C. −6=−(32−4⋅3)(31cos(3⋅3+2))+(92)⋅3sin(3⋅3+2)−(31)cos(3⋅3+2)+C.
Find f(−2): Combine like terms to get the final expression for f(x). f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)−(31)cos(3x+2).Use the initial condition f(3)=−6 to find the constant of integration C. Substitute x=3 into the expression for f(x) and solve for C. −6=−(32−4⋅3)(31cos(3⋅3+2))+(92)⋅3sin(3⋅3+2)−(31)cos(3⋅3+2)+C. Calculate the trigonometric values and solve for C. f(x)0. f(x)1. f(x)2. f(x)3.
Find f(−2): Combine like terms to get the final expression for f(x). f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)−(31)cos(3x+2).Use the initial condition f(3)=−6 to find the constant of integration C. Substitute x=3 into the expression for f(x) and solve for C. −6=−(32−4⋅3)(31cos(3⋅3+2))+(92)⋅3sin(3⋅3+2)−(31)cos(3⋅3+2)+C. Calculate the trigonometric values and solve for C. f(x)0. f(x)1. f(x)2. f(x)3. Now that we have C, we can find f(−2) by substituting f(x)6 into the expression for f(x). f(x)8.
Find f(−2): Combine like terms to get the final expression for f(x). f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)−(31)cos(3x+2).Use the initial condition f(3)=−6 to find the constant of integration C. Substitute x=3 into the expression for f(x) and solve for C. −6=−(32−4⋅3)(31cos(3⋅3+2))+(92)⋅3sin(3⋅3+2)−(31)cos(3⋅3+2)+C. Calculate the trigonometric values and solve for C. f(x)0. f(x)1. f(x)2. f(x)3. Now that we have C, we can find f(−2) by substituting f(x)6 into the expression for f(x). f(x)8. Calculate the trigonometric values and simplify to find f(−2). f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)−(31)cos(3x+2)0.
Find f(−2): Combine like terms to get the final expression for f(x). f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)−(31)cos(3x+2).Use the initial condition f(3)=−6 to find the constant of integration C. Substitute x=3 into the expression for f(x) and solve for C. −6=−(32−4⋅3)(31cos(3⋅3+2))+(92)⋅3sin(3⋅3+2)−(31)cos(3⋅3+2)+C. Calculate the trigonometric values and solve for C. f(x)0. f(x)1. f(x)2. f(x)3. Now that we have C, we can find f(−2) by substituting f(x)6 into the expression for f(x). f(x)8. Calculate the trigonometric values and simplify to find f(−2). f(x)=−(x2−4x)(31cos(3x+2))+(92)xsin(3x+2)−(31)cos(3x+2)0. Use a calculator to find the trigonometric values and compute f(−2) to the nearest thousandth. This step requires a calculator, and the exact values will depend on the calculator's output.
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