Trigenometric equation. (1 Viewer)

D

deltaxray

Guest
Can someone help me solve the following trig equations?


1. 5sin^2(x) -4sin(x) cos(x)+3cos^2(x) = 2

2. 3 tan(x)-2 cot(x)+3 sec(x) = 0

thanks.
 

Lukybear

Active Member
Joined
May 6, 2008
Messages
1,466
Gender
Male
HSC
2010
1.5sin^2(x) -4sin(x) cos(x)+3cos^2(x) = 2

Divide everything by cos^2 or sin^2

5tan^2x-4tan^2x+3 = 2sec^2
5tan^2x-4tan^2x+3 = 2tan^2x+2
3tan^2x-4tanx+1=0
tanx = 1/3 or 1
x = 18degree 26 min, or 45 degree
 

Lukybear

Active Member
Joined
May 6, 2008
Messages
1,466
Gender
Male
HSC
2010
2.3 tan(x)-2 cot(x)+3 sec(x) = 0

3(sinx/cosx) - 2(cosx/sinx) + 3/cosx = 0

3sin^2x - 2(cos^2x) + 3sinx = 0
simplify:
5sin^2x+3sinx-2 =0
etc...
solve
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top