The given integral is
f(x)=∫(x2+2x−1516x+24)dx.
Factorizing the denominator, we get
x2+2x−15=(x+5)(x−3).
Using partial fractions, we can write:
(x+5)(x−3)16x+24=x+5A+x−3B16x+24=A(x−3)+B(x+5)Substituting
x=3, we get
72=8B⇒B=9.
Substituting
x=−5, we get
−56=−8A⇒A=7.
Therefore, the integral becomes:
f(x)=∫(x+57+x−39)dxf(x)=7loge∣x+5∣+9loge∣x−3∣+CGiven
f(4)=14loge(3), we substitute
x=4:
f(4)=7loge(9)+9loge(1)+C=14loge(3)+CSince
f(4)=14loge(3), we get
C=0.
Thus,
f(x)=7loge∣x+5∣+9loge∣x−3∣.
Now, substituting
x=7:
f(7)=7loge(12)+9loge(4)f(7)=7loge(22⋅3)+9loge(22)f(7)=7(2loge(2)+loge(3))+18loge(2)f(7)=14loge(2)+7loge(3)+18loge(2)f(7)=32loge(2)+7loge(3)f(7)=loge(232⋅37)Comparing this with
f(7)=loge(2α⋅3β), we get
α=32 and
β=7.
Therefore,
α+β=32+7=39.
Answer:
39