Cofunction identities - Trigonometric Identities

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Trigonometric Identities Topics:

Cofunction identities

Lessons

Notes:
Cofunction Identities: Basically, we need the sum of the left and right brackets to be 90° or π2\frac{\pi}{2}

sin⁡(π2−θ)=cos⁡(θ)\sin(\frac{\pi}{2}-\theta)=\cos(\theta)
sin⁡(θ)=cos⁡(π2−θ)\sin(\theta)=\cos(\frac{\pi}{2}-\theta)
tan⁡(π2−θ)=cot⁡(θ)\tan(\frac{\pi}{2}-\theta)=\cot(\theta)
tan⁡(θ)=cot⁡(π2−θ)\tan(\theta)=\cot(\frac{\pi}{2}-\theta)
sec⁡(π2−θ)=csc⁡(θ)\sec(\frac{\pi}{2}-\theta)=\csc(\theta)
sec⁡(θ)=csc⁡(π2−θ)\sec(\theta)=\csc(\frac{\pi}{2}-\theta)
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Cofunction identities

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