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CHAPTER 2: RIGHT TRIANGLES

ANSWERS

SIMILAR TRIANGLES:

1. What is 1 condition that makes 2 triangles to be similar?o Two

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sin A = O / H cos A = A / H tan A = O / A

o How to remember this? ( SOH-CAH-TOA) or (SOHCAHTOA)o Relationship of the 3 main trig. Functions and their reciprocals?

csc A = 1 / sin A sec A = 1 / cos A cot A = 1 / tan A

o Units of trig. Functions? No units. Why? Trig. Functions are just ratio of sides. Units cancel out

oRelationship of tan with sin and cos

tan A = sin A / cos A12.Trig. Functions of special

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15.Using trig. Functions in real-world applications:o Angle of elevation?

o Angle of depression?

Or Simply:

FINDING THE ANGLE:

16.What does it mean by sin-1y or arcsiny?o Is another way of writing o Or = sin-1y = arcsiny

17.How do we find the angle given the trig. Functions(y is just a number):o sin = y then = sin-1yo cos = y then = cos-1yo tan = y then = tan-1yo csc = y then = csc-1yo sec = y then = sec-1yo cot = y then = cot-1y

COFUNCTION THEOREM:

18.Statement:o

If A, B are complementary, then: trig. Function of one = cofunction ofanother.o That is:

sin A = cos B and vice versa tan A = cot B and vice versa sec A = csc B and vice versa

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19.What does it mean?o It means:

sin 30 = cos 60 tan 52 = cot 38 sec 10 = csc 80

20.Converse:o A, B are some angles.

If trig. Function of one = cofunction of another, then A and B arecomplementary.

21.What does it mean? It means:o Given:

sin A = cos B then A + B = 90 tan A = cot B then A + B = 90 sec A = csc B then A + B = 90