Question

5) Use a calculator and find to 4 decimal places the value of the trigonometric function using the given identity.
2u = 64° , cos 2u = 1 -2 sin ^2 u
a.) 0.0792

b.) 0.3327

c.) 0.9992

d.) 0.5629

e.) 0.4384

Answer 1

Answer:

cos(2u) = 1 - 2$sin^{2}$(32°) = 1 - (2$\times$0.281 )  =   1  -  0.5616  = 0.4384

Hence the correct option is E.) 0.4384

Step-by-step explanation:

i) 2u = 64°

ii) u = 32°

iii) sin(32°) = 0.53

iv) $sin^{2}$(32°) = $(0.53)^{2}$  =  0.2808

v) cos(2u) = 1 - 2$sin^{2}$(32°) = 1 - (2$\times$0.2808 )  =   1  -  0.5616  = 0.4384

Hence the correct option is E.) 0.4384