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Solve the trig equations 2sin^2(x) + sin(x) - 1 =0

  • #1

Homework Statement



Find all values of x in the interval 0<=x<=2pi for which 2sin^2(x)+sin(x)-1=0.

Homework Equations





The Attempt at a Solution



I have no idea.

I spent awhile trying to figure it out on my graphics calculator but couldn't figure it out.

I have only been told how to solve trig equations where there is 1 trig function, lol.

any help would be great thanks.
 

Answers and Replies

  • #2
2,063
2
This equation is quadratic, the variable is sin(x). Can you solve now?
 
  • #3
1,752
1
ax^2+bx+c=0

quadratic formula ...

for trig

x=trig identity
 
  • #4
o rite i see.

I think I have the right answers lol

cheeers
 
  • #5
1,752
1
o rite i see.

I think I have the right answers lol

cheeers
You can always check it by plugging it back into your original equation.
 

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