Page 14 - Ebook Trigonometri_Krisna Hasugian_MESP 2019

Example 5

a) Use the triangle below to find the six trig ratios

First use Pythagorean Theorem to find the hypotenuse

a² + b² = c², where a and b are legs of the right triangle and c is the
hypotenuse
sin = = = csc = =
4
1
5
8

ℎ 10 5 sin 4
6² + 8² = ²
cos = = = sec = 1 =
3

6
5

36 + 64 = ² ℎ 10 5 cos 3

4
3
8
100 = ² tan = = = cot = 1 =
6 3 tan 4

√100 = √ ²
10 =
Example 6
Use the triangle below to find the six trig ratios

1² + ² = (√5 )² sin = = 2√5 csc =
√5
2
√5 5 2
1 + ² = 5
√5
cos = = √5 sec = = √ 5
1
² = 4 √5 5 1
2 1
= 2 tan = = 2 cot =
1
2

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