Posted by Abby on Saturday, March 6, 2010 at 6:12pm.
Approximate the equation's soultions in the interval (o, 2pi). If possible find the exact solutions.
sin 2x sinx = cosx
I do not know where to start.

PreCal  MathMate, Saturday, March 6, 2010 at 11:15pm
Expand sin 2x using the identity:
sin2x=2sin(x)cos(x)
We'll get:
2cos(x)sin²(x)=cos(x)
Transpose lefthandside to the right:
2cos(x)((1/2)sin²(x))=0
So
cos(x)=0, or
sin²(x)=1/2
Solve for x in (0,2π) as specified.
Answer This Question
Related Questions
 PreCal  Approximate the equation's soultions in the interval (o, 2pi). If ...
 PreCal(Please check)  Approximate the equation's solutions in the interval (0,...
 Math Help  Hello! Can someone please check and see if I did this right? Thanks...
 precal/trig  PlEASE help me with this!! I need it as soon as possible....... ...
 Math  Approximate the equation's solutions in the interval (0,2pi). sin2x sinx...
 PreCal (Please help)  Find all the soultions of the equation in the interval...
 Trigonometry.  ( tanx/1cotx )+ (cotx/1tanx)= (1+secxcscx) Good one! Generally...
 pre cal  Find all solutions in the interval[0,2pi),cos x/2sinx=0
 Precalculus  Please help!!!!!!!!!!! Find all solutions to the equation in the ...
 Math  Pre Clac  Prove that each of these equations is an identity. A) (1 + ...
More Related Questions