sine question?

1 ⤊

What is the value of sine pi/2?
What is the value of r on this (sin = y/r)?

Im just confused..tnx..=D

2007-09-13 02:21:42 · 2 answers · asked by bnj 3 in Science & Mathematics ➔ Mathematics

2 answers

sin(pi/2) = 1
r = 1

Picture a unit circle. R is always 1 regardless of the angle. You have to go back to the definition of the unit circle.

Pi/2 is 90 degrees, which is streight up on the y axis. Sin of that is, of course 1, because y is 1, and r is 1.

2007-09-13 02:31:28 · answer #1 · answered by tkquestion 7 · 1⤊ 0⤋

sin(pi/2) = 1.

If sin(t) = y / r looks like a part of the relationship between cartesian (x, y) and polar (r, t) co-ordinates.
The relationships are:
x = r cos(t)
y = r sin(t)
x^2 + y^2 = r^2.

2007-09-13 02:31:53 · answer #2 · answered by Anonymous · 0⤊ 0⤋