Homework Help: Math

Posted by Jake on Wednesday, January 25, 2012 at 10:06pm.

How many solutions does the equation cosx + 1/2 = 1 have for 0<x<2pi

cosx+1/2=1
cosx+1=2
cosx=2-1
cosx=1

therefore 1 solution?

A) 1
b) 2
c) 3
d) 4

Math - Reiny, Wednesday, January 25, 2012 at 10:54pm
What did you do ????

cosx + 1/2 = 1
cosx = 1/2
the cosine is positive in quads I and IV
x = 30° or x = 330° or (π/6 and 11π/6)

so obviously 2 solutions between 0 and 2π
Math - Jake, Wednesday, January 25, 2012 at 11:08pm
How come I am not suppose to get rid of the the denominator?
Math - Reiny, Thursday, January 26, 2012 at 8:30am
if you had multiplied by 2 then your second line should have been

2cosx + 1 = 2 . and then
2cosx = 1
cosx = 1/2 , now pick it up in my solution.

you forgot to multiply the cosx by 2

Answer this Question

Related Questions

Math - Verify the identity . (cscX-cotX)^2=1-cosX/1+cosX _______ sorry i cant ...
Pre-Calc - Trigonometric Identities Prove: (tanx + secx -1)/(tanx - secx + 1)= ...
Trigonometry Check - Simplify #3: [cosx-sin(90-x)sinx]/[cosx-cos(180-x)tan...
Maths - Solve this equation fo rx in the interval 0<=x<=360 ...
Trig........ - I need to prove that the following is true. Thanks (cosx / 1-sinx...
grouping - i am trying to solve for A and B....this question comes from a ...
Math - Proving identity (sinx+tanx)/(cosx+1)=tanx RS: (sinx+(sinx/cosx))/(cosx+1...
RESPONSE to PreCalc Question - h t t p : / / w w w . j i s k h a . c o m / d i s...
Trigonometry. - ( tanx/1-cotx )+ (cotx/1-tanx)= (1+secxcscx) Good one! ...
Math - Pre- Clac - Prove that each of these equations is an identity. A) (1 + ...

For Further Reading

First Name:
School Subject:
Answer: