# maths

posted by Vin Mwale

if cosine A=0•8 find sine B

1. Damon

I guess you mean find sin A because I have no idea what B is

cos^2 + sin^2 = 1
0.8^2 + sin^2 = 1
sin^2 = 1-0.64 = 0.36
sin = +/- sqrt(0.36)

2. Steve

as shown above, sinA = ±0.6

or, you can see that if you draw a triangle, it is just a scaled-down 3-4-5 triangle. so if sinA = 4/5, cosA = 3/5.

## Similar Questions

1. ### Graphing trigonometric function

sine and cosine have a period 2pi tangent and cotangent have period pi Can someone explain why?
2. ### Trigonometry

I had to find the sine, cosine and tangent of -150 degrees. I got - sq. root of 3/2, -1/2, and - sq. root of 3/3. But my book has -1/2 as the sine, and -sq. root of 3/3 as the cosine. Why is this?
3. ### trigonometry

in triangle abc, angle c is a right angle, AC=8,Bc=15 and AB=17 a.find Sine a b.Find cosine A c.Find Sine B d. Find COsine B E. the measure of angel A f. the measure of angela b Can u tell me the answers and how to do it. Because im …
4. ### cosine and sine HELP!

Simplify and write the trigonometric expression in terms of sine and cosine: ((2+tan^2 x)(sec^2 x))-1 = (f(x))^2 f(x)= ?
5. ### sine and cosine

Simplify and write the trigonometric expression in terms of sine and cosine: sin x + (cot x)(cos x) = (1/f(x)) f(x)= ?
6. ### Algebra 2....

1. An artist is designing triangular mirrors. Determine the number of different triangles that she can form using the given measurements. Then solve the triangles. Round to the nearest tenth. a=4.2 cm b= 5.7 cm measure angle A= 39 …
7. ### Algebra 2 ..

1. An artist is designing triangular mirrors. Determine the number of different triangles that she can form using the given measurements. Then solve the triangles. Round to the nearest tenth. a=4.2 cm b= 5.7 cm measure angle A= 39 …
8. ### Algebra2---

1. An artist is designing triangular mirrors. Determine the number of different triangles that she can form using the given measurements. Then solve the triangles. Round to the nearest tenth. a=4.2 cm b= 5.7 cm measure angle A= 39 …
9. ### maths

Sine and Cosine rule are both used in solving trigonometry problems.Give an example of when the cosine rule is more appliciable than the sine rule?
10. ### Geometry

The word cosine literally means "the complement of the sine." Write a paragraph explaining how complements of sine and cosine are connected. I know that the sine and the cosine of complementary angles are the same. but how can i add …

More Similar Questions