Asked by Anonymous
2(sinx)^2-5cosx-4=0
Answers
Answered by
bobpursley
change sin^2x to 1-cos^2x, then
2-2cos^2x-5cosx-4=0
let u= cosx
2-2u^2-5u-4=0
2u^2+5u+2=0
(2u+1)(U+2)=0
u=-1/2 u=-2
cosx=-1/2
x=330 deg disregard second answer, you are not dealing with hyperbolic trig functions yet (but there is a solution in the complex plane)
2-2cos^2x-5cosx-4=0
let u= cosx
2-2u^2-5u-4=0
2u^2+5u+2=0
(2u+1)(U+2)=0
u=-1/2 u=-2
cosx=-1/2
x=330 deg disregard second answer, you are not dealing with hyperbolic trig functions yet (but there is a solution in the complex plane)
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.