lisaboden54021 lisaboden54021
  • 26-04-2018
  • Mathematics
contestada

Find the exact value of the trigonometric expression given cos (22.5 ).

Respuesta :

Аноним Аноним
  • 29-04-2018
use the identity   cos^2 (a/2) =  1/2 (1 + cos a) so

cos^ 2 22.5  = cos^2 (45/2)  = 1/2 ( 1 + cos 45)  =  1/2(1 + sqrt2/ 2)4 = 1/2 + sqrt2/4

cos 22.5  =  sqrt ( 1/2 + sqrt2/4)  Answer
Answer Link

Otras preguntas

I am factor of 48, I am bigger than 4 square. I am smaller than 5. WHAT IS THE MYSTERY NUMBER
Y = {x | x Element of Set N and 16 < x < 25} ?
The recommended dose of Vancocin® for a severe staphylococcal infection is 40 mg/kg/day.  The adult weighs 180 pounds and is to receive the medication IV q6h
what does 'blow by blow' mean?
how to plot m>0 on a number line
what is choreography? please help
Perform the operations, multiply, and simplify.-a^3b (3a^2 b^5 - ab^4 - 7a ^2 b)
a stone is dropped from the top of 50 m high tower simultaneously another stone is thrown upward with a speed of 20 m/s . calculate the time at which both the s
I need to find the zeros of the function:f(x)=2x^2-5x-3
(a-6b)(a+6b) pls answer