English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

im trying to study for a test but i really dont get how to do this? please help!!!

2007-07-13 17:39:43 · 5 answers · asked by ? 2 in Science & Mathematics Mathematics

5 answers

Recall the trig identity:

sin^2(x)+cos^2(x)=1

So sin^2(x)=1-cos^2(x)

We substitute:

1-cos^2(x)+cos(x)=1

cos^2(x)-cos(x)=0

cos(x) (cos(x)-1)=0

cos(x)=0

x=pi/2, 3pi/2

cos(x)-1=0

x=0, 2pi

Answers: x=0, pi/2, 3pi/2, 2pi

2007-07-13 17:53:52 · answer #1 · answered by Red_Wings_For_Cup 3 · 0 0

sin^2 x + cos x = 1
1 - cos^2 x + cos x = 1
- cos^2 x + cos x = 0
cos^2 x - cos x = 0
cos x(cos x - 1) = 0
cos x = 0
x = π/2, 3π/2
cos x = 1
x = 0, 2π

x = 0, π/2, 3π/2, 2π

2007-07-14 00:54:12 · answer #2 · answered by Helmut 7 · 1 0

1 - cos ² x + cos x = 1
cos ² x - cos x = 0
cos x (cos x - 1) = 0
cos x = 0 , cos x = 1
x = π/2 , 3π/2 , 0 , 2π

2007-07-14 04:33:49 · answer #3 · answered by Como 7 · 0 0

Woops

2007-07-14 01:08:22 · answer #4 · answered by Rob 2 · 0 0

less

2007-07-14 00:44:04 · answer #5 · answered by um jake 2 · 0 0

fedest.com, questions and answers