Question

Given angel theta with cos theta < 0 and sin theta > 0, indicate the quadrant that theta lies in

Answer 1

Answer:

Cos 0 = 1 which is greater than 0

Cos 90 = 0 which is equal to 0

Cos 180 = -1 which is less than 0

Cos 270 = 0 which is equal to 0

that means thetha must be in second or third quadrant.

now Sin 0 = 0

Sin 90 = 1

Sin 180 = 0

Sin 270 = -1

that means thetha must be in third or fourth quadrant.

But the solution must satisfy both the condition

cos thetha < 0 and sin thetha > 0 which is only possible in the third quadrant.

hence thetha lies in the third quadrant