Algebra 2
posted by jeff .
I meant to type this one:
If the sine of an acute angle is 0.8, what is the sine of twice that angle?
1.60 or .64?
Thanks

Neither. Sine can never exceed 1.
If the sine is 0.8, the cosine is 0.6.
(Think of a 3,4,5 right triangle, or use cos^2 = 1  sin^2)
The sine is 2x is 2 sinx cosx.
In this case, that is 2*(3/5)(4/5)= 24/25
Respond to this Question
Similar Questions

Math
calculus help needed example: sin1(1/2) how do you figure this out? 
Physics
When light of a certain wavelength is incident normally on a certain diffraction grating the line of order 1 is at a diffraction angle of 25 degrees. The diffraction angle of the second order line is : a) 25 b) 42 c) 50 d) 58 e) 75 … 
PreCalc (Sine)
I'm having trouble understanding a sine concept. For instance, I know that the sine of 15 is .25881. Likewise, the sine of 165 is also .25881. How can I find other values of sine that also equal .25881? 
Trigonometry
Cos D= 3/4. if the sine of the angle is positive, find the sine of the angle and determine the quadrant. Can anyone tell me the steps. I need to learn this. 
trig
The tangent of an acute angle equals 1/2. What is the sine of the angle? 
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 … 
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 … 
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 … 
math
Which statement is ALWAYS true? A) The sine of an angle is equal to the sine of the angle's complement. B) The cosine of an angle is equal to the sine of the angle's supplement. C) The sine of an angle is equal to the cosine of the 
Math
While evaluating the sine of a particular angle, an absent minded student failed to notice that his calculator was not in the correct angular mode. He was very lucky to end up with the right answer. What are the two smallest possible …