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Evaluate `int cos^(3)x sqrt(sinx)dx`. |
Answer» [ Here, the power of cos x is 3, which is an odd positive integer. Therefore, put `dz=cos x dx`. Now, `int cos^(3)x sqrt(sinx)dx=int cos^(2)x sqrt(sinx)cos x dx` `=int(1-sin^(2)x)sqrt(sinx)cosx dx` `=int (1-z^(2))sqrt(z) dz` `=int (sqrt(z)-z^(5//2))dz` `=(z^(3//2))/(3//2)-(z^(7//2))/(7//2)+c=(2)/(3)z^(3//2)-(2)/(7)z^(7//2)+c` `=(2)/(3)"sin"^(3//2)x-(2)/(7)"sin"^(7//2)x+c` |
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