pre cal
posted by ali .
assume the angle is in the first quadrant, and sin theta equals 1/5. what is sin 2 theta?

sin(theta)=1/5
cos(theta)=sqroot[1sin(teta)^2]
cos(theta)=sqroot[1(1/5)^2]
cos(theta)=sqroot(11/25)
cos(theta)=sqroot(25/251/25)
cos(theta)=sqroot(24/25)
cos(theta)=sqroot(6*4/25)
cos(theta)=sqroot(6*2^2/5^2)
cos(theta)=(2/5)*sqroot(6)
sin(2theta)=2*sin(theta)*cos(theta)
sin(2theta)=2*(1/5)*(2/5)sqroot(6)
sin(2theta)=(4/25)*sqroot(6)
Respond to this Question
Similar Questions

Pre Cal
sin theta  2sin^2 theta = 0 I'm using the up carrot sign to signal "to the power of..." Let sin theta = x x  2 x^2 = 0 x (1  2x) = 0 Both x=0 and x = 1/2 are solutions. theta = 0 degrees, 30 degrees, 150 degrees and 180 degrees. … 
simple trig
If sin(theta)=[sqrt(70)]/7 and theta is in Quadrant two, find the exact numerical value of tan theta without using a calculator. I got tan(theta)=[sqrt(294)]/42 Is that right? 
easy trig
If sin(theta)=[sqrt(70)]/7 and theta is in Quadrant two, find the exact numerical value of tan theta without using a calculator. I got tan(theta)=[sqrt(294)]/42 Is that right? 
Calculus
I wanted to confirm that I solved these problems correctly (we had to convert the polar curves to Cartesian equations). 1.rcos(theta)=1 x=1 2.r=2*sin(theta)+2*cos(theta) r^2=2rsin(theta)+2rcos(theta) x^2+y^2=2y+2x (a little unsure … 
math
if sin theta equals 3/5 and theta is second quadrant angle find tan 2 theta.my ans. was 3.442 but is wrong can you correct and show work please. thank you so much. 
trig
If sin 2 theta = (2/5) in Quadrant 2, find sin theta, cos theta, tan theta, and draw triangle theta. 
Math
1. Let (7, 4) be a point on the terminal side of (theta). Find the exact values of sin(theta), csc(theta), and cot(theta). 2. Let (theta) be an angle in quadrant IV such that sin(theta)=2/5. Find the exact values of sec(theta) and … 
Algebra II
Multiple Choice Which expression is NOT equivalent to 1? 
trig
If sin theta is equal to 5/13 and theta is an angle in quadrant II find the value of cos theta, sec theta, tan theta, csc theta, cot theta. 
Math Calc
Let theta be an angle in the first quadrant, and suppose sin theta equals a. Evaluate sin(180 degrees + theta) in terms of a sin(180 degrees + theta) =