A few days ago
b country90

need help evaluating these trigonometric equations.?

1) sin^-1(-1/2)

2) sin^2 (5pi/6)

3) cot(2pi/3)

4) cot^-1(-1)

5) sec (3pi/4)

Top 2 Answers
A few days ago
Not Eddie Money

Favorite Answer

1)The angle whose sine is -1/2 is -30 degrees, or -Pi/6 radians. Therefore the arcsin (as you’ve written sin^-1 (-1/2)) is -Pi/6, or if you would prefer to keep the answer positive instead, 11*Pi/6 radians. The answer could also be in quadrant 3, at 7*Pi/ 6 radians.

2) Similarly, since sin(5*Pi/6) is 1/2, (sin(5Pi/6))^2= (1/2)^2 =1/4

3) cot(x) = 1/(tan(x)) = cos(x)/sin(x)

cos(2*Pi/3) = -1/2, sin(2*Pi/3) = sqrt(3)/2,

so cot(2*Pi/3) = (-1/2)/(sqrt(3)/2) = -1/sqrt(3)

4) see above for definition of cotangent. Then for cos(x)=sin(x), |x| = Pi/4, or 45 degrees.

Since this is negative, it can either be in quadrant 2 or quadrant 4. so the answer could be 3*Pi/4 or 7*Pi/4.

5)sec(x) = 1/cos(x). cos(3*Pi/4) = -1/sqrt(2)

so sec(3*Pi/4) = -sqrt(2)

0

A few days ago
plb5000
do you have your graphing calculator handy?…these are great calculator questions…
0