English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

how can find the integrals of cos(x)-sin(x)/sin(x)+cos(x)?

2006-07-30 06:48:30 · 7 answers · asked by star123 2 in Science & Mathematics Mathematics

7 answers

The above solution is correct. You could also say that we need to perform the following u-substitution:

u = sin x + cos x
du = cos x - sin x.

After this substitution, the integrand becomes (1/u)du. You should know the integral of this! It's ln(u) + C. Plugging back in for u gives us the final answer:

ln ( sin x + cos x ) + C.

BTW, when you state a problem like this you should use parentheses and say

(cos x - sin x)/(sin x + cos x).

What you wrote actually says something different than what you probably *meant* to say.

2006-07-30 06:51:47 · answer #1 · answered by Aaron 3 · 2 1

U-substitution would work here:

Integral {dx * [cos(x)-sin(x)] / [sin(x)+cos(x)] }

u = sin(x) + cos(x) and du= cos(x) - sin(x) dx

So,
Integral {dx * [cos(x)-sin(x)] / [sin(x)+cos(x)] }
= Integral {du/u}
= ln u + C
=ln [sin(x) + cos(x)] + C

2006-07-30 21:24:37 · answer #2 · answered by Anonymous · 0 0

INTEGRAL OF [cos(x)-sin(x)/sin(x)+cos(x)]dx =
INTEGRAL OF [2cos(x)-1]dx =
-2sin(x) - x + C

2006-07-30 13:54:58 · answer #3 · answered by fcas80 7 · 0 0

put sin(x)+ cos(x) = y
dy/dx = cos(x) - sin(x)
so integral = ln Y + c
= lin(sin(x)+cos(x)) + c

2006-07-30 13:51:34 · answer #4 · answered by Mein Hoon Na 7 · 0 0

integ ((cos x - sin x)/(sin x + cos x)).dx

Let t = sinx + cos x
dt = (cos x - sin x).dx

therefore, integ (dt/t)
= log t
= log (sinx + cos x)

2006-07-31 01:38:41 · answer #5 · answered by chan_l_u 2 · 0 0

kpt is right

2006-07-30 13:54:31 · answer #6 · answered by zxcpoi 4 · 0 0

you can use a calculator

2006-07-30 13:52:06 · answer #7 · answered by laserman 2 · 0 0

fedest.com, questions and answers