Monday

March 30, 2015

March 30, 2015

Posted by **usha** on Saturday, June 11, 2011 at 6:54am.

- trig -
**drwls**, Saturday, June 11, 2011 at 7:55am0.6 cosč + 0.8 sinč = 0.9

Let sinx = 0.6; then

cosx = 0.8 and x = 36.87 degrees

sinx cosč + cosx sinč = 0.9

sin (x + č) = 0.9

x + č = 64.16 degrees or 115.84 degrees

alpha = č1 = 27.29 degrees

beta = č2 = 78.97

alpha + beta = 106.26 degrees

sin (alpha + beta) = 0.9600

- trig -
**Reiny**, Saturday, June 11, 2011 at 8:16amdrwls,

that is amazingly clever.

- trig -
**usha**, Saturday, June 11, 2011 at 10:21amthank you very much. can u solve the same by quadratic equation method

- trig -
**drwls**, Saturday, June 11, 2011 at 11:24amyes, it can be done that way, but I'd rather leave that to you.

Write it as

6cosθ= 9 - 8 sinθ

Square both sides and the left side can be written 36(1 - sin^2 θ)

Then you have a quadratic in sin theta to solve. Have fun.

**Answer this Question**

**Related Questions**

math - if alpha and beta are 2 different values of θ lying between 0 and 2...

trignometry - if alpha and beta are 2 different values of θ lying between 0...

trig - evaluate the following in exact form, where the angeles alpha and beta ...

Math - Calculus - The identity below is significant because it relates 3 ...

Precalc/Trig - Sorry there are quite a few problems, but I just need to know if ...

trig - cosθ =5/13 with -π/2 < θ <0 find each of the ...

Trig - Given that csc θ = -4 and tan θ > 0, find the exact value of...

mathematics - given sinθ=-5/13 and π<θ<3π/2 find sin2...

math - given sinθ=-5/13 and π<θ<3π/2 find sin2θ ...

trigonometry - if cosθ=2/3 and tanθ<0 find the exact value sin(&#...