Wednesday

August 20, 2014

August 20, 2014

Posted by **Hujinson** on Tuesday, April 14, 2009 at 9:20pm.

sin(arccosx-arcsin3x)

2. The cosx=4/5, x lies in quadrant 4. Find sin x/2

3.Determine all solutions in (0,2pie) for sin4xsin^2x=3,

cot^2v(3-1)cotx=v(3), cos^2x=cosx, and

tan^2x-6tanx+4=0

4. Solve; sin(∏/2-x)=1/sec

5. Solve; cot+4x+2cot^2x+1=csc4x

6. Solve; tan(x+∏/x=(√(3)+3tanx)/(3-√(3)tanx

- Math-Trig -
**Reiny**, Tuesday, April 14, 2009 at 10:42pmWow! You actually want somebody to do that assignment for you, without showing any effort on your part?

I will start off with #2, then you let us know some of your steps and work

use cos 2A = 1 - 2sin^2 A

then cos x = 1 - 2sin^2 x/2

4/5 = 1 - 2sin^2 x/2

solve for sin x/2

you will end up with sin x/2 = ±1/√10

but you are told that x is in quadrant IV, so x/2 must be in quadrant II and

sin x/2 = 1/√10

- Math-Trig -
**Hujinson**, Tuesday, April 14, 2009 at 11:25pmOk, so because sin=opp/hyp and sec=hyp/adj it will be √10/

- Math-Trig -
**Reiny**, Tuesday, April 14, 2009 at 11:56pmno, because I solved the equation 4/5 = 1 - 2sin^2 x/2

2sin^2 x/2 = 1 - 4/5

sin^2 x/2 = 1/10

take √ of both sides

sin x/2 = ± 1/√10

why are you talking about secant?

the problem dealt only with sines and cosines.

**Related Questions**

trig - express this in sinx (1/ cscx + cotx )+ (1/cscx- cotx) i got 2sinx is ...

Trigonometry - Prove the following trigonometric identities. please give a ...

TRIG.............. - Q.1 Prove the following identities:- (i) tan^3x/1+tan^2x + ...

Trigonometry. - ( tanx/1-cotx )+ (cotx/1-tanx)= (1+secxcscx) Good one! ...

Trig....... - I need to prove that the following is true. Thanks (2tanx /1-tan^x...

Trig Identities - Proving identities: 1) 1+ 1/tan^2x = 1/sin^2x 2) 2sin^2 x-1 = ...

TRIGONOMETRY *(MATHS) - Q.1 Prove the following identities:- (i) tan^3x/1+tan^2x...

trig - please help me with some questions I skipped on a review for our test ...

Confused! Pre-Cal - Verify that each equation is an identity.. tan A= sec a/csca...

another precal - i have two questions for you to check please! 6cos^2x+5cosx-4=0...