## anonymous 5 years ago Use a coterminal angle to find the exact value of the expression. Do not use a calculator. Seleccione una respuesta. a. b. c. d.

1. anonymous

are you spanish? and where is the question and options

2. anonymous

$\cos405$

3. anonymous

cos405=cos(360+45)=cos45=1/root(2)

4. anonymous

5. anonymous

No tengo idea de ángulo coterminal ....... lo siento

6. anonymous

but the answer i found is.707

7. ash2326

co405=cos(360+45) cos (A+B)=cosAcosB-sinAsinB cos(360+45)=cos(360)cos(45)-sin(360)sin(45) cos360=1 sin360=0 sin45=cos45=1/sqrt(2) so cos405=1/sqrt(2) or 0.707

8. ash2326

$1/\sqrt(2)$=1/1.414=0.707

9. anonymous

but ash2326 , in options there is no .707

10. ash2326

you wrote before that answer given is 0.707

11. anonymous

Use a coterminal angle to find the exact value of the expression. Do not use a calculator. $\cos 405$° Choose the rifht answer: |dw:1322555209852:dw|

12. ash2326

sariah it's 1st option $1/\sqrt(2) =\sqrt(2)/2$