Posted by **ken** on Friday, April 25, 2014 at 5:55am.

given that sin (2x+30)=cos(x-15).determine the value of x given x is an acute angle

- algebra -
**Steve**, Friday, April 25, 2014 at 6:13am
assuming that x is in degrees, then knowing that cos(x) = sin(90-x), we have

sin(2x+30) = sin(90-(x-15))

sin(2x+30) = sin(105-x)

so,

2x+30 = 105-x

3x = 75

x = 25

check:

sin(80) = cos(10)

yep.

## Answer this Question

## Related Questions

- Math - 1. Write the expression as a function of an acute angle whose measure is ...
- MATH - 1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL ...
- Math - How does the related acute angle help to determine the trigonometric ...
- Trigonometry - find (acute) angle A, given: a. sin A = 0.4919 b. tan A = 2.7775 ...
- algebra - Can someone please help me do this problem? That would be great! ...
- pre-cal - Simplify the given expression........? (2sin2x)(cos6x) sin 2x and cos ...
- Trig - Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < ...
- trig - Reduce the following to the sine or cosine of one angle: (i) sin145*cos75...
- math - Can you please check my work. A particle is moving with the given data. ...
- Trigonometry - If cos(a)=1/2 and sin(b)=2/3, find sin(a+b), if 1) Both angles ...

More Related Questions