Integrate the following function: f(x) = 8x^3 + 1/x + 5

We can see that the function is a sum of three terms so we can deal with each term separately and add them up. The term 8x3 and 5 are relatively straightforward and follow the standard rules for integration: "raise the power by 1 and divide by the new power". Therefore 8x^3 becomes 8/4 x4 = 2x4 and the 5 becomes 5x. Then we look at the 1/x term. This is slightly more complicated as it we cannot follow that rule since, remembering 1/x is the same as x-1, this would give us x0/0 which can't be true. Instead, we know that 1/x integrates to ln(x) (the natural logarithm). Finally, as with all indefinite integratals (integration without limits) we have to add a constant. The final answer is therefore 2x4 + ln(x) + 5x + c

EJ

Related Maths A Level answers

All answers ▸

Show how to derive the quadratic formula


If the functions f and g are defined: f: x--> x/5 + 4 g : x--> 30x + 10. what is x, if fg(x) = x. ?? What would fgf(x) = x^2 be??


How do you find the point of intersection of two vector lines?


How to prove that (from i=0 to n)Σi^2= (n/6)(n+1)(2n+1), by induction.