# pre-cal

posted by .

show solution

solve. 2sin^(2)x=2+cosx

• pre-cal -

2 (1-cos^2 x) = 2 + cos x
2 - 2 cos^2 x = 2 + cos x
cos x + 2 cos^2 x = 0
cos x ( 1 + 2 cos x) = 0
cos x = 0 ---> x = 90 degrees (pi/2 radians etc)
cos x = -1/2 ---> x = 120 degrees, 240 degrees etc

## Similar Questions

1. ### Pre-Calc

Trigonometric Identities Prove: (tanx + secx -1)/(tanx - secx + 1)= tanx + secx My work so far: (sinx/cosx + 1/cosx + cosx/cosx)/(sinx/cos x - 1/cosx + cosx/cosx)= tanx + cosx (just working on the left side) ((sinx + 1 - cosx)/cosx)/((sinx …
2. ### Math - Trig - Double Angles

Prove: sin2x / 1 - cos2x = cotx My Attempt: LS: = 2sinxcosx / - 1 - (1 - 2sin^2x) = 2sinxcosx / - 1 + 2sin^2x = cosx / sinx - 1 = cosx / sinx - 1/1 = cosx / sinx - sinx / sinx -- Prove: 2sin(x+y)sin(x-y) = cos2y - cos2x My Attempt: …
3. ### math

solve each equation for 0=/<x=/<2pi sin^2x + 5sinx + 6 = 0?
4. ### Pre-Calc

Establish the identity. sinx + cosx/sinx - cosx = 1+2sinxcosx/2sin^2x-1
5. ### Pre-Cal

Use the fundamental identities to simplify the expression. csc Q / sec Q so this would be 1/sinx / 1/cosx and then 1/sinx times cosx/1 = sin x cosx Is this correct so far?
6. ### pre cal

find the exact value of tan(2sin-1 3/5)
7. ### Pre Cal

simplify the expression 2sin^2 t + cos^2 t-2
8. ### Math

Solve each equation for 0≤x<2π 1. (cosX)(cosX+1)=0 2. 2sin^2(X)-3sinX=2
9. ### pre-cal

solve for all values in [0,2pie) 2sin^2x-1=0
10. ### Math

I am having trouble with a pre-cal problem. If you could explain how to do it that would be great! ((3^3)^(cosx+2/3sinx))^2cosx+3sinx all divided by ((3^sinx)^13)^cosx = x

More Similar Questions