Asked by lola

How do I get exact measures?
cosine 270 degrees
sin 90 degrees
tan 360 degrees
csc 45 degrees
no calculator!

Answers

Answered by MathMate
The best way to solve these problems is to draw a unit circle (radius = 1), and calculate these ratios from the definitions (cosine = adjacent / hypotenuse, etc.)
The first three can be solved easily this way. The last one,
csc(45°)=1/sin(45°)
Knowing that sin(45)=cos(45), and
sin²(45)+cos²(45)=1, we solve for sin(45)=(√2)/2, so
csc(45)=2/√2 = √2.

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