Simplify the integral: Let's start by simplifying the integral a bit, we have:∫z(z2+1)e2dzNotice that e2 is a constant and can be factored out of the integral.So, we get:e2⋅∫z(z2+1)1dz
Partial fraction decomposition: Now, let's do a partial fraction decomposition on z(z2+1)1. We want to express z(z2+1)1 as zA+z2+1Bz+C. To find A, B, and C, we multiply both sides by z(z2+1) and compare coefficients. 1=A(z2+1)+(Bz+C)z
Find coefficients: Setting z=0 to find A gives us:1=A∗(0+1)So, A=1.
Integrate term by term: Now we need to find B and C. We can plug in different values for z or compare coefficients. Let's compare coefficients for the z2, z, and constant terms. For z2 terms: 0=A+B For z terms: 0=C For constant terms: 1=A We already know C0, so C1 and C2.
Substitute and integrate: Now we have our partial fraction decomposition:z(z2+1)1=z1−z2+1zSo the integral becomes:e2⋅∫(z1−z2+1z)dz
Combine logarithms: Let's integrate term by term.The integral of z1dz is ln∣z∣.The integral of −z2+1zdz is a bit trickier, but we can use a substitution.Let u=z2+1, then du=2zdz.
Final simplification: We substitute and get:∫−z2+1zdz=−21∫u1duWhich integrates to −21ln∣u∣.
Final simplification: We substitute and get:∫−z2+1zdz=−21∫u1duWhich integrates to −21ln∣u∣.Now we substitute back for u to get the integral in terms of z.−21ln∣u∣ becomes −21ln∣z2+1∣.
Final simplification: We substitute and get:∫−z2+1zdz=−21∫u1duWhich integrates to −21ln∣u∣.Now we substitute back for u to get the integral in terms of z.−21ln∣u∣ becomes −21ln∣z2+1∣.Putting it all together, we have:e2⋅(ln∣z∣−21ln∣z2+1∣)+C
Final simplification: We substitute and get:∫−z2+1zdz=−21∫u1duWhich integrates to −21ln∣u∣.Now we substitute back for u to get the integral in terms of z.−21ln∣u∣ becomes −21ln∣z2+1∣.Putting it all together, we have:e2⋅(ln∣z∣−21ln∣z2+1∣)+CFinally, we can simplify a bit by combining the logarithms:e2⋅ln∣(z2+1)21z∣+C
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