Trigonometric Identities: Class 10 Mathematics Worksheet

The key identity is sin²θ + cos²θ = 1, and from the definitions tan θ = sin θ/cos θ, sec θ = 1/cos θ and cosec θ = 1/sin θ follows 1 + tan²θ = sec²θ. Class 10 students pick the correct identity, definition or value (such as tan 0° = 0) from four options in each multiple-choice question, for a score out of 15.