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Expressing ratios in other ratios
Expressing ratios in other ratios
Last updated at May 29, 2023 by Teachoo
Example 9 Express the ratios cos A, tan A and sec A in terms of sin A. cos A Since, cos2 A + sin2 A = 1 cos2 A = 1 β sin2 A cos A = Β±β(1 βπ ππ2 π΄) Here, A is acute (i.e. less than 90Β°) & cos A is positive when A is acute So, cos A = β(1 βπ ππ2 π΄) sec A sec A = π/ππ¨π¬β‘γ π¨γ sec A = 1/β(1 βπ ππ2 π΄) tan A We know that tan A = πππβ‘γ π¨γ/πππβ‘γ π¨γ Putting value of cos A tan A = sinβ‘γ π΄γ/β(1 β π ππ2 π΄)