Another one m — let's solve it.
Here are the solutions for the definite integrals using the substitution method.
I) For the integral ∫063x−26xdx:
Step 1: Define the substitution and find the differential.
Let u=3x−2.
Then du=3dx, which means dx=31du.
Also, from u=3x−2, we have 3x=u+2, so 6x=2(u+2).
Step 2: Change the limits of integration.
When x=0, u=3(0)−2=−2.
When x=6, u=3(6)−2=18−2=16.
Step 3: Substitute into the integral and simplify.
∫−216u2(u+2)⋅31du=32∫−216uu+2du=32∫−216(1+u2)du
Step 4: Integrate and evaluate using the new limits.
32[u+2ln∣u∣]−216
32[(16+2ln∣16∣)−(−2+2ln∣−2∣)]
32[16+2ln(16)+2−2ln(2)]
32[18+2(ln(16)−ln(2))]
32[18+2ln(216)]
32[18+2ln(8)]
32⋅2[9+ln(8)]
34[9+ln(8)]=12+34ln(8)
Since ln(8)=ln(23)=3ln(2), the answer can also be written as:
12+34(3ln(2))=12+4ln(2)
The final answer is 12+4ln(2).
II) For the integral ∫56x−41−2xdx:
Step 1: Define the substitution and find the differential.
Let u=x−4.
Then du=dx.
Also, from u=x−4, we have x=u+4. So 1−2x=1−2(u+4)=1−2u−8=−2u−7.
Step 2: Change the limits of integration.
When x=5, u=5−4=1.
When x=6, u=6−4=2.
Step 3: Substitute into the integral and simplify.
∫12u−2u−7du=∫12(−2−u7)du
Step 4: Integrate and evaluate using the new limits.
[−2u−7ln∣u∣]12
[(−2(2)−7ln∣2∣)−(−2(1)−7ln∣1∣)]
[−4−7ln(2)]−[−2−7(0)]
−4−7ln(2)+2
−2−7ln(2)
The final answer is −2−7ln(2).
III) For the integral ∫032x+82x−3dx:
Step 1: Define the substitution and find the differential.
Let u=2x+8.
Then du=2dx, which means dx=21du.
Also, from u=2x+8, we have 2x=u−8. So 2x−3=(u−8)−3=u−11.
Step 2: Change the limits of integration.
When x=0, u=2(0)+8=8.
When x=3, u=2(3)+8=6+8=14.
Step 3: Substitute into the integral and simplify.
∫814uu−11⋅21du=21∫814(1−u11)du
Step 4: Integrate and evaluate using the new limits.
21[u−11ln∣u∣]814
21[(14−11ln∣14∣)−(8−11ln∣8∣)]
21[14−11ln(14)−8+11ln(8)]
21[6+11(ln(8)−ln(14))]
21[6+11ln(148)]
21[6+11ln(74)]
3+211ln(74)
The final answer is 3+211ln(74).
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