solve the integral ill post to down
\[\int\limits_{}\sqrt{1 + sinx}*dx\]
We use a right triangle and Pythagoras theorem for substitutionse: /| / | / | / | 1 / | u / | /x | -------- Now we can use the Pythagorean Theorem to find the third side, and then the cosine of x. The third side is sqrt(1 - u^2), and so: cos(x) = sqrt(1 - u^2) Our integral is now: sqrt(1 + u) INT ------------- du sqrt(1 - u^2) Now I can't help but notice that 1 - u^2 = (1 - u)(1 + u) so this fraction simplifies to: 1 INT ----------- du sqrt(1 - u) We are almost done. We have now transformed our trig integral into an algebraic integral. Now a second substitution: w = 1 - u should finish the job. If w = 1 - u, then dw = -du, so du = -dw. This gives: 1 - INT ------- dw sqrt(w) Interpret this as w^(-1/2), and we can use the formula for antidifferentiating u^n: 1 - INT ------ dw = -2w^(1/2) + C sqrt(w) Now change back from w to u using w = 1 - u: -2w^(1/2) = -2 sqrt(1 - u) + C And now change back from u to x using u = sin(x): -2w^(1/2) = -2 sqrt(1 - u) + C = -2 sqrt(1 - sin(x)) + C I hope that helps.
really thanks
u r welcome.... do u think i hv done it right??????
well i have to check it...
ok, do so and let me know.........
^^
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