Answer: D
Step-by-step explanation:
Answer:
1
Step-by-step explanation:
2-1=1
Given: sin theta = 2/5. This tells us that the lengths of the opp side and the hyp are 2 and 5 respectively. The adj side is found using the Pyth. Thm.: 5^2-2^2= 25-4 = 21, so that the adj side is sqrt(21).
The double angle formula for the sine is sin 2theta = 2 sin theta *cos theta.
In this particular problem, the sine of 2theta is 2*(2/5)*[sqrt(21) / 5], or:
(4/25)*sqrt(21).
To find the decimal value of a fraction, you simply divide the numerator by the denominator. In this case, we are dividing 4 by 20, which is equal to .2. Therefore, the decimal value that is equal to 4/20 is 0.2.
