Problem

Consider the function f(x) whose second derivative is f(x)=10x+3sin(x). If f(0)=2 and f(0)=3, what is f(4) ?

Answer

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Answer

Therefore, the value of f(4) is 32033sin(4)+26.

Steps

Step 1 :Given that the second derivative of the function f(x) is f(x)=10x+3sin(x), we can find the first derivative f(x) by integrating f(x) with respect to x.

Step 2 :The integral of 10x with respect to x is 5x2 and the integral of 3sin(x) with respect to x is 3cos(x). Therefore, f(x)=5x23cos(x)+C, where C is the constant of integration.

Step 3 :Given that f(0)=3, we can substitute x=0 into the equation f(x)=5x23cos(x)+C to find the value of C. This gives 3=5(0)23cos(0)+C, which simplifies to C=3+3=6. Therefore, f(x)=5x23cos(x)+6.

Step 4 :We can find the function f(x) by integrating f(x) with respect to x. The integral of 5x2 with respect to x is 53x3, the integral of 3cos(x) with respect to x is 3sin(x), and the integral of 6 with respect to x is 6x. Therefore, f(x)=53x33sin(x)+6x+D, where D is the constant of integration.

Step 5 :Given that f(0)=2, we can substitute x=0 into the equation f(x)=53x33sin(x)+6x+D to find the value of D. This gives 2=53(0)33sin(0)+6(0)+D, which simplifies to D=2. Therefore, f(x)=53x33sin(x)+6x+2.

Step 6 :Finally, we can find the value of f(4) by substituting x=4 into the equation f(x)=53x33sin(x)+6x+2. This gives f(4)=53(4)33sin(4)+6(4)+2.

Step 7 :Calculating the above expression gives f(4)=53(64)3sin(4)+24+2.

Step 8 :Simplifying the above expression gives f(4)=32033sin(4)+26.

Step 9 :Therefore, the value of f(4) is 32033sin(4)+26.

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