general solution  cos (4x-60)=sin2x [-90:90]  

Expert Answers

An illustration of the letter 'A' in a speech bubbles

Solve `cos(4x-60^@)=sin2x ` :

`cos(4x-60^@)=sin2x `

`sin(4x+30^@)=sin2x `

Take the inverse sine of both sides:

1. `4x+30=180-2x+360n ` where n is an integer.




2. 4x+30=2x+360n




The general solution is x=25+60n for n an integer or x=-15+180n for n an integer.

On the interval [-90,90] the solutions are x=-35,-15,25,85

Here is the graph: the left side in black and the right side in red:

convert the scale from radian to degrees.
Approved by eNotes Editorial Team

We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

  • 30,000+ book summaries
  • 20% study tools discount
  • Ad-free content
  • PDF downloads
  • 300,000+ answers
  • 5-star customer support
Start your 48-Hour Free Trial