The derivative of the function f is defined by f′(x)=(x3−5x)cos(2x). If f(−1)=−4, then use a calculator to find the value of f(6) to the nearest thousandth.Answer:
Q. The derivative of the function f is defined by f′(x)=(x3−5x)cos(2x). If f(−1)=−4, then use a calculator to find the value of f(6) to the nearest thousandth.Answer:
Integrate f′(x): To find f(6), we need to integrate f′(x) from −1 to 6 and add the result to f(−1).
Apply integration by parts: The integral of f′(x) is ∫(x3−5x)cos(2x)dx. We will use integration by parts and trigonometric identities to solve this.
Integrate (21)sin(2x)(3x2−5)dx: Let u=x3−5x, then du=(3x2−5)dx. Let dv=cos(2x)dx, then v=(21)sin(2x) using the integral of cosine.
Apply integration by parts again: Using integration by parts, ∫udv=uv−∫vdu. We apply this to our integral: ∫(x3−5x)cos(2x)dx=21x3sin(2x)−∫21sin(2x)(3x2−5)dx.
Integrate −23xcos(2x)dx: We now need to integrate ∫21sin(2x)(3x2−5)dx. This requires another integration by parts.
Combine all parts of the integral: Let u=(3x2−5), then du=6xdx. Let dv=(21)sin(2x)dx, then v=−(41)cos(2x) using the integral of sine.
Evaluate the definite integral: Applying integration by parts again, we get ∫(21)sin(2x)(3x2−5)dx=−(41)(3x2−5)cos(2x)−∫−(41)cos(2x)(6x)dx.
Calculate f(6): The remaining integral is ∫−(41)cos(2x)(6x)dx, which simplifies to ∫−(23)xcos(2x)dx. This requires another integration by parts.
Calculate f(6): The remaining integral is ∫−(41)cos(2x)(6x)dx, which simplifies to ∫−(23)xcos(2x)dx. This requires another integration by parts.Let u=−3x, then du=−3dx. Let dv=(21)cos(2x)dx, then v=(41)sin(2x).
Calculate f(6): The remaining integral is ∫−(41)cos(2x)(6x)dx, which simplifies to ∫−(23)xcos(2x)dx. This requires another integration by parts.Let u=−3x, then du=−3dx. Let dv=(21)cos(2x)dx, then v=(41)sin(2x).Applying integration by parts, we get ∫−(23)xcos(2x)dx=(41)(−3x)sin(2x)−∫(41)(−3)sin(2x)dx.
Calculate f(6): The remaining integral is ∫−(41)cos(2x)(6x)dx, which simplifies to ∫−(23)xcos(2x)dx. This requires another integration by parts. Let u=−3x, then du=−3dx. Let dv=(21)cos(2x)dx, then v=(41)sin(2x). Applying integration by parts, we get ∫−(23)xcos(2x)dx=(41)(−3x)sin(2x)−∫(41)(−3)sin(2x)dx. The remaining integral is ∫(41)(−3)sin(2x)dx, which simplifies to −(43)∫sin(2x)dx. The integral of ∫−(41)cos(2x)(6x)dx0 is ∫−(41)cos(2x)(6x)dx1.
Calculate f(6): The remaining integral is ∫−(41)cos(2x)(6x)dx, which simplifies to ∫−(23)xcos(2x)dx. This requires another integration by parts.Let u=−3x, then du=−3dx. Let dv=(21)cos(2x)dx, then v=(41)sin(2x).Applying integration by parts, we get ∫−(23)xcos(2x)dx=(41)(−3x)sin(2x)−∫(41)(−3)sin(2x)dx.The remaining integral is ∫(41)(−3)sin(2x)dx, which simplifies to −(43)∫sin(2x)dx. The integral of ∫−(41)cos(2x)(6x)dx0 is ∫−(41)cos(2x)(6x)dx1.So, ∫−(41)cos(2x)(6x)dx2. Now we combine all parts of the integral we've calculated.
Calculate f(6): The remaining integral is ∫−(41)cos(2x)(6x)dx, which simplifies to ∫−(23)xcos(2x)dx. This requires another integration by parts.Let u=−3x, then du=−3dx. Let dv=(21)cos(2x)dx, then v=(41)sin(2x).Applying integration by parts, we get ∫−(23)xcos(2x)dx=(41)(−3x)sin(2x)−∫(41)(−3)sin(2x)dx.The remaining integral is ∫(41)(−3)sin(2x)dx, which simplifies to −(43)∫sin(2x)dx. The integral of ∫−(41)cos(2x)(6x)dx0 is ∫−(41)cos(2x)(6x)dx1.So, ∫−(41)cos(2x)(6x)dx2. Now we combine all parts of the integral we've calculated.The integral from ∫−(41)cos(2x)(6x)dx3 to ∫−(41)cos(2x)(6x)dx4 of ∫−(41)cos(2x)(6x)dx5 is the sum of all the parts we've integrated by parts. We need to evaluate this definite integral and add it to ∫−(41)cos(2x)(6x)dx6.
Calculate f(6): The remaining integral is ∫−(41)cos(2x)(6x)dx, which simplifies to ∫−(23)xcos(2x)dx. This requires another integration by parts.Let u=−3x, then du=−3dx. Let dv=(21)cos(2x)dx, then v=(41)sin(2x).Applying integration by parts, we get ∫−(23)xcos(2x)dx=(41)(−3x)sin(2x)−∫(41)(−3)sin(2x)dx.The remaining integral is ∫(41)(−3)sin(2x)dx, which simplifies to −(43)∫sin(2x)dx. The integral of ∫−(41)cos(2x)(6x)dx0 is ∫−(41)cos(2x)(6x)dx1.So, ∫−(41)cos(2x)(6x)dx2. Now we combine all parts of the integral we've calculated.The integral from ∫−(41)cos(2x)(6x)dx3 to ∫−(41)cos(2x)(6x)dx4 of ∫−(41)cos(2x)(6x)dx5 is the sum of all the parts we've integrated by parts. We need to evaluate this definite integral and add it to ∫−(41)cos(2x)(6x)dx6.We evaluate the integral at the bounds ∫−(41)cos(2x)(6x)dx4 and ∫−(41)cos(2x)(6x)dx3, subtract the lower bound evaluation from the upper bound evaluation, and add the result to ∫−(41)cos(2x)(6x)dx6.
Calculate f(6): The remaining integral is ∫−(41)cos(2x)(6x)dx, which simplifies to ∫−(23)xcos(2x)dx. This requires another integration by parts.Let u=−3x, then du=−3dx. Let dv=(21)cos(2x)dx, then v=(41)sin(2x).Applying integration by parts, we get ∫−(23)xcos(2x)dx=(41)(−3x)sin(2x)−∫(41)(−3)sin(2x)dx.The remaining integral is ∫(41)(−3)sin(2x)dx, which simplifies to −(43)∫sin(2x)dx. The integral of ∫−(41)cos(2x)(6x)dx0 is ∫−(41)cos(2x)(6x)dx1.So, ∫−(41)cos(2x)(6x)dx2. Now we combine all parts of the integral we've calculated.The integral from ∫−(41)cos(2x)(6x)dx3 to ∫−(41)cos(2x)(6x)dx4 of ∫−(41)cos(2x)(6x)dx5 is the sum of all the parts we've integrated by parts. We need to evaluate this definite integral and add it to ∫−(41)cos(2x)(6x)dx6.We evaluate the integral at the bounds ∫−(41)cos(2x)(6x)dx4 and ∫−(41)cos(2x)(6x)dx3, subtract the lower bound evaluation from the upper bound evaluation, and add the result to ∫−(41)cos(2x)(6x)dx6.Using a calculator to evaluate the integral at ∫−(23)xcos(2x)dx0 and ∫−(23)xcos(2x)dx1, we find the change in ∫−(23)xcos(2x)dx2 over this interval. We then add this change to ∫−(23)xcos(2x)dx3 to find f(6).
Calculate f(6): The remaining integral is ∫−(1/4)cos(2x)(6x)dx, which simplifies to ∫−(3/2)xcos(2x)dx. This requires another integration by parts. Let u=−3x, then du=−3dx. Let dv=(1/2)cos(2x)dx, then v=(1/4)sin(2x). Applying integration by parts, we get ∫−(3/2)xcos(2x)dx=(1/4)(−3x)sin(2x)−∫(1/4)(−3)sin(2x)dx. The remaining integral is ∫(1/4)(−3)sin(2x)dx, which simplifies to −(3/4)∫sin(2x)dx. The integral of ∫−(1/4)cos(2x)(6x)dx0 is ∫−(1/4)cos(2x)(6x)dx1. So, ∫−(1/4)cos(2x)(6x)dx2. Now we combine all parts of the integral we've calculated. The integral from ∫−(1/4)cos(2x)(6x)dx3 to ∫−(1/4)cos(2x)(6x)dx4 of ∫−(1/4)cos(2x)(6x)dx5 is the sum of all the parts we've integrated by parts. We need to evaluate this definite integral and add it to ∫−(1/4)cos(2x)(6x)dx6. We evaluate the integral at the bounds ∫−(1/4)cos(2x)(6x)dx4 and ∫−(1/4)cos(2x)(6x)dx3, subtract the lower bound evaluation from the upper bound evaluation, and add the result to ∫−(1/4)cos(2x)(6x)dx6. Using a calculator to evaluate the integral at ∫−(3/2)xcos(2x)dx0 and ∫−(3/2)xcos(2x)dx1, we find the change in ∫−(3/2)xcos(2x)dx2 over this interval. We then add this change to ∫−(3/2)xcos(2x)dx3 to find f(6). After calculating the definite integral and adding it to ∫−(3/2)xcos(2x)dx3, we round the result to the nearest thousandth to get the final answer.
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