Jawaban:

a) 1 - cos²30 = sin² 30

1 - ( cos 30)² = ( sin 30)²

1 - ( ½√3)² = (½)²

1 - (¼ x 3) = ¼

1 - 3/4 = ¼.

4/4 - 3/4 = ¼

b) 1 - sin² 45 = cos² 45

1 - (½√2)² = ( ½√2)²

1 - ¼ x 2 = ¼ x 2

1 - ½ = ½

2/2 - ½ = ½

c) sin² 60 + cos² 60 = 1

(sin 60)² + ( cos 60)² = 1

( ½√3)² + ( ½)² = 1

¼ x 3 + ¼ = 1

¾ + ¼ = 1

d) -1 + sec² 30 = tan² 30

-1 + ( 1/cos 30)² = ( tan 30)²

-1 + ( 1/ ½√3)² = (⅓√3)²

-1 + ( 1 / ¼ x 3) = ⅑ x 3

-1 + ( 1/3/4 ) = 3/9

-1 + 3/4 = ⅓

-3/3 + 4/3 = ⅓

⅓ = ⅓

e) sec² 45 - tan² 45 = 1

( 1 / cos 45)² - ( Tan)² = 1

( 1/ ½√2)² - ( 1 )² = 1

( 1 / ¼ x 2) - 1 = 1

( 1/ 2/4 ) - 1 = 1

1 / ½ - 1 = 1

2/1 - 1 = 1

2 - 1 = 1

f) 1 + tan²60 = sec² 60

1 + ( Tan 60)² = ( sec 60)²

1 + ( √3)² = ( 1/ cos 60)²

1 + 3 = (1 / ½)²

4 = (2/1)²

4 = 4

g) cosec² 30 - cot²30 = 1

(cosec 30)² - (√3)² = 1

( 1/ sin 30)² - 3 = 1

( 1/ ½)² - 3 = 1

2² - 3 = 1

4 - 3 = 1

h) -1 + cosec² 45 = cot² 45

-1 + (1/sin 45)² = ( 1)²

-1 + ( 1/ √2/2)² = 1

-1 + (1/ 2/4) = 1

-1 + 4/2 = 1

-1 + 2 = 1