Which of the following is true? sin² 60⁰ + cos² 60⁰ = 1, sin² 45⁰ + cos² 45⁰ = 1, sin² 45⁰ − cos² 45⁰ = 0, All of these

sin² 60⁰ + cos² 60⁰ = 1

sin² 45⁰ + cos² 45⁰ = 1

sin² 45⁰ − cos² 45⁰ = 0

All of these

Let's evaluate each option:

1. sin² 60⁰ + cos² 60⁰ = 1

sin 60⁰ = √3/2, cos 60⁰ = 1/2

(√3/2)² + (1/2)² = 3/4 + 1/4 = 1

2. sin² 45⁰ + cos² 45⁰ = 1

sin 45⁰ = cos 45⁰ = 1/√2

(1/√2)² + (1/√2)² = 1/2 + 1/2 = 1

3. sin² 45⁰ − cos² 45⁰ = 0

(1/√2)² - (1/√2)² = 1/2 - 1/2 = 0