1. imagine you are looking for a certain angle whose cosine is positive and whose sine is negative

part 1: name the two quadrants in which cosine is positive

part 2: name the quadrants in which sine is negative

part 3: use the information in parts a and b to identify the quadrant in which cosine is positive and sine is negative

part 4: write down one angle, in degrees, that has a negative sine and a positive cosine

part 5: using your calculator confirm your choice by writing the cosine of your angle and the sine of your angle below

2. Sam used his calculator to find cos 1.75

part 1: when no unit is given for an angle, what unit must be used?

part 2: in which quadrant is an angle of 1.75 found?

part 3: in this quadrant is the value of cosine positive of negative

part 4: sam used his calculator to find the answer and wrote down cos 1.75=0.999. Does this seem like a reasonable answer to you

part 5: what might he have done wrong on his calculator

3. sarah used her calculator to find sin125

part 1: in which quadrant is the angle 125 located?

part 2: in this quadrant, is the value of sine positive or negative?

part 3: sarah used her calculator to find the answer and wrote down sin 125 =-0.57. does this seem like a reasonable answer to you?

part 4: what might she have done wrong on her calculator?