We know that
sin²x+cos²x=1
so
clear cos x
cos x=(+/-)√[1-sin²x]
in this problem
<span>Angle 0 is in quadrant 1 -----> cos o and sin o are positive
</span>sin o=2/5
cos x=√[1-(2/5)²]----> cos o=√[1-4/25]----> cos o=√[21/25]---> cos o=√21/5
the answer is
cos o=√21/5
Answer:
x = 0
Step-by-step explanation:
Step 1: Write equation
-19 = x - 19
Step 2: Solve for <em>x</em>
- Add 19 to both sides: 0 = x
- Rewrite: x = 0
Step 3: Check
<em>Plug in x to verify it's a solution.</em>
-19 = 0 - 19
-19 = -19