Posted by Marie on Friday, August 3, 2012 at 3:47pm.
cot(2A) = X/Y = 5/12. Q1.
r^2 = 5^2 + 12^2 = 169
r = 13.
cos(2A) = X/r = 5/13.
sin(2A) = Y/r = 12/13.
tan(2A) = Y/X = 12/5.
cos2A = 2cos^2A-1 = 5/13
2cos^2A = 5/13 + 1 = 18/13
cos^2A = 18/26
cosA = sqrt(18/26)
cosA = 3sqrt(2/26)
cosA = 3*sqrt(1/13).
sqrt = Square root.
sin(2A) = 2sinA*cosA = 12/13.
2sinA*3sqrt(1/13) = 12/13
sinA*3sqrt(1/13) = 12/26
sinA = (12/26)/(3sqrt(1/13)
sinA = (4/26)/(sqrt(1/13)
sinA = (2/13)/(sqrt(1/13)
sinA = (2/13)sqrt(1/13)/(1/13)
sinA = 2sqrt(1/13).
Related Questions
trig - given that 0 is less then or equal to theta and theta is less then or ...
algebra/trigonometry - What are the values of theta in the interval 0degrees ...
Precalculs - I have no idea how to do these type of problems. -------Problem...
Trigonometry - Thank you STEVE!!!!! Suppose that Cos (theta) = 1/square root 2 ...
trig - If tan theta = sin theta, and theta is greater than or equal to 0 and ...
Calculus - If cos2 theta = 1/3 and 0 is less than or equal to 2 theta and 2 ...
Trigonometry - a. Find the exact value of sin (theta - pi/6) b. Find the exact ...
trig - If sin theta = x and -pi/2 is less than or equal to theta less than or ...
Algebra II - Which of the following expressions are not equal to 1? A) sin^2 ...
trig - What are the values of theta in the interval 0 less than or equal to ...
For Further Reading
