X xomandi New member Joined Oct 1, 2006 Messages 31 May 6, 2007 #1 int (sinx/cos x^2) dx do i have to convert this to a different identity before trying to integrate?? well sin/cos = tan but we have a cos^2 ahhh I am confused! Please help!
int (sinx/cos x^2) dx do i have to convert this to a different identity before trying to integrate?? well sin/cos = tan but we have a cos^2 ahhh I am confused! Please help!
skeeter Elite Member Joined Dec 15, 2005 Messages 3,204 May 6, 2007 #2 hint ... \(\displaystyle \L \frac{\sin{x}}{\cos^2{x}} = \frac{1}{\cos{x}} \cdot \frac{\sin{x}}{\cos{x}}\)
hint ... \(\displaystyle \L \frac{\sin{x}}{\cos^2{x}} = \frac{1}{\cos{x}} \cdot \frac{\sin{x}}{\cos{x}}\)
X xomandi New member Joined Oct 1, 2006 Messages 31 May 6, 2007 #3 ohh alright so 1/cos x * sin x/cos x = sec x tan x int (sec x tan x) dx = sec x + c is that right?!
M mindy88 New member Joined Apr 11, 2007 Messages 30 May 6, 2007 #4 couldn't you just do u subsitution? so, u= cos x du= sin x so you would jus have to integrate 1/(u^2)
couldn't you just do u subsitution? so, u= cos x du= sin x so you would jus have to integrate 1/(u^2)
X xomandi New member Joined Oct 1, 2006 Messages 31 May 6, 2007 #5 mindy88 said: couldn't you just do u subsitution? so, u= cos x du= sin x so you would jus have to integrate 1/(u^2) Click to expand... i think i was taught a completely different way i have no idea what you mean
mindy88 said: couldn't you just do u subsitution? so, u= cos x du= sin x so you would jus have to integrate 1/(u^2) Click to expand... i think i was taught a completely different way i have no idea what you mean
skeeter Elite Member Joined Dec 15, 2005 Messages 3,204 May 6, 2007 #6 xomandi said: ohh alright so 1/cos x * sin x/cos x = sec x tan x int (sec x tan x) dx = sec x + c is that right?! Click to expand... that is correct. you'll learn the method of substitution soon enough.
xomandi said: ohh alright so 1/cos x * sin x/cos x = sec x tan x int (sec x tan x) dx = sec x + c is that right?! Click to expand... that is correct. you'll learn the method of substitution soon enough.
