Tuharramah
New member
- Joined
- Jun 18, 2017
- Messages
- 13
You can see question in photo below
Please tell me identities and/or other stuff to solve this.
[FONT=MathJax_Math-italic]c[/FONT][FONT=MathJax_Math-italic]o[/FONT][FONT=MathJax_Math-italic]s[/FONT][FONT=MathJax_Size3]([/FONT][FONT=MathJax_Main]3[/FONT][FONT=MathJax_Math-italic]π/[/FONT][FONT=MathJax_Main]2[/FONT][FONT=MathJax_Main]−[/FONT][FONT=MathJax_Main]2[/FONT][FONT=MathJax_Math-italic]x[/FONT][FONT=MathJax_Size3])[/FONT][FONT=MathJax_Main]+[/FONT][FONT=MathJax_Math-italic]s[/FONT][FONT=MathJax_Math-italic]i[/FONT][FONT=MathJax_Math-italic]n[/FONT][FONT=MathJax_Main]([/FONT][FONT=MathJax_Math-italic]π[/FONT][FONT=MathJax_Main]−[/FONT][FONT=MathJax_Main]3[/FONT][FONT=MathJax_Math-italic]x[/FONT][FONT=MathJax_Main])[/FONT][FONT=MathJax_Main]=[/FONT][FONT=MathJax_Math-italic]s[/FONT][FONT=MathJax_Math-italic]i[/FONT][FONT=MathJax_Math-italic]n[/FONT][FONT=MathJax_Main]([/FONT][FONT=MathJax_Main]3[/FONT][FONT=MathJax_Math-italic]x[/FONT][FONT=MathJax_Main])[/FONT][FONT=MathJax_Main]−[/FONT][FONT=MathJax_Math-italic]c[/FONT][FONT=MathJax_Math-italic]o[/FONT][FONT=MathJax_Math-italic]s[/FONT][FONT=MathJax_Main]([/FONT][FONT=MathJax_Math-italic]x[/FONT][FONT=MathJax_Main])You can see question in photo below
Please tell me identities and/or other stuff to solve this.
View attachment 8164
I got x as 30 deg.
Unfortunately i couldn't upload my solution
So is it correct answer?
Was your domain restricted like: 0 ≤ x ≤ π/2So it will be:
-2sin (x)×cos (x)+cos (x)=0
2sin (x)×cos (x)-cos (x)=0
Cos (x) × (2sin (x) -1)=0
X1=90
X2=30
..
So when I divided by cos x ,I killed one solution