Tuesday

March 3, 2015

March 3, 2015

Posted by **ALISON** on Thursday, September 15, 2011 at 10:27pm.

[pie/2, pie]

sin s = radical2/ whole number 2

what is s in radians?

how do i figure this out without the use of a calculator. I drew the graph and located it in the second quadrant and i think the triangle is a 45-45-90 but i don't how to find the radians for the sin of s.

- Trig -
**Reiny**, Thursday, September 15, 2011 at 11:42pmstart with this equation:

π radians = 180°

now divide this by simple whole numbers

e.g.

divide by 2 ---> π/2 = 90°

divide by 3 ---> π/3 = 60°

divide by 4 ---> π/4 = 45°

divide by 5 ---> π/5 = 36

divide by 6 ---> π/6 = 30°

divide by 8 ---> π/8 = 22.5°

etc.

copy this chart into a handy place in your notebook.

you know that the sine is positive in the first and 2nd quadrant.

Since s of sin s in in the second quadrant,

s = π - π/4 = 3π/4 , (180-45 = 135°)

check:

sin 3π/4 = .707106781... = √2/2

**Answer this Question**

**Related Questions**

calculus - Hi i have two questions: what is the exact value of cos 5(pie)/12? ...

physics - The motion of a particle is described by x = 10 sin (piet +pie/2 ). At...

maths - Choose the two options which are true for all values of x 1) cos (x) = ...

Calculus grade 12 - solve for (<_ = less than or equal to / pie = pie sign...

trig - i can not figure out how to write the complex number in rectangular form ...

math - evaluate the expressions below and leave them in radical form. 1. sin(pie...

trig - use a sum or difference identity to find an exact value cos pie/12

trig identies 5.3 &5.4 - use a sum or difference identity to find an exact value...

Trig - Use the half angle formula to find the exact value of tan 7 pie/8

precal - use the half angle formula to determine the exact values of sin, cos, ...