How do solve the following integral? (t+7)2t3dt

(t+7)2t3dt

2 Answers
Dec 4, 2017

Just expand the function and integrate. The answer is lnt14t492t2+C.

Explanation:

Let f(t)=(t+7)2t3. First, let's rearrange f(t) into simpler terms.
f(t)=t2+14t+49t3
=1t+14t2+49t3
=t1+14t2+49t3

Then integrate f(t). Note that xndx=1n+1xn+1+C if n1, where C is the integral constant. If n=1, x1dx=(1x)dx=lnx+C is applied.

f(t)dt=(t1+14t2+49t3)dt
=t1dt+14t2dt+49t3dt
=lnt+14(t1)+49(12t2)+C
=lnt14t492t2+C.

Dec 4, 2017

ln(t)7(4t+7)2t2+c

Explanation:

solving (t+7)2

(t+7)2=t2+14t+49

now in the integral

t2+14t+49t3dt

separating the fractions

(t2t3+14tt3+49t3)dt

1t+14t2+49t3dt

separting

1tdt=ln(t)+c

14t2dt=14t+c

49t3dt=492t2+c

1t+14t2+49t3dt=ln(t)14t492t2+c

operating

1t+14t2+49t3dt=ln(t)7(4t+7)2t2+c

t2+14t+49t3dt=ln(t)7(4t+7)2t2+c