Question

2cos theta = sec theta.. what are they asking me to find?

Answer 1

\[\theta\]

Answer 2

\[2\cos\theta=\sec\theta\]

Answer 3

the exact values of the degree?

Answer 4

i would think so

Answer 5

on what interval?

Answer 6

0 degree to 360 degree

Answer 7

\[2\cos{\theta}=\sec{\theta} \rightarrow 2\cos{\theta}=\frac{1}{\cos{\theta}}\]then\[2\cos^2{\theta}=1\]

Answer 8

\[\cos{\theta}={\pm}\frac{1}{\sqrt{2}}\]

Answer 9

Find all those angles theta that satisfy this.

Answer 10

θ = 45, 215, 135, 225

Answer 11

itsmesowat.. how'd you get the answers?

Answer 12

use your unit circle or other favorite method to get special angle values for consine...

Answer 13

use the calculator do [2nd] [cos] of the fraction 1/rad(2)

Answer 14

Draw a right-angled triangle with sides 1, 1 and hypotenuse sqrt(2). cos(theta)=1/sqrt(2) when theta = 45 degrees. In the second quadrant, 180-45 = 135 degrees, in the third, 180+45 degrees = 225 and in the fourth, 360-45 = 315 degrees/

Answer 15

gotcha.

Answer 16

you got everything lokisan said? you are a genius!!~~~~

Answer 17

lol tyler.. where'd you get 215 degrees?

Answer 18

215 is typo, should be 225, which is 180+45, reference angle of 135

Answer 19

gotcha.

Answer 20

sorry i suck at typing out math...
they should introduce the white board on this haha

Answer 21

lmao. XD

Answer 22

they have these equation thingys. it's built from mathjax

Answer 23

wait. how'd you get 1/sqrt of 2?

Answer 24

2cos^2(theta)=1. Divide both sides by 2, then take the sqrt of both sides.