Answer:
cosθ = c/√1+c²
Explanation:
Given cot θ = c and 0 < θ < π/2
In trigonometry identity:
cotθ = 1/tanθ = c
1/tanθ = c
cross multiply
tanθ = 1/c
According to SOH, CAH, TOA:
Tanθ = opposite/adjacent = 1/c
cosθ = adjacent/hypotenuse
To get the hypotenuse, we will use the pythagoras theorem:
hyp² = opp²+adj²
hyp² = 1²+c²
hyp = √1+c²
Find cosθ in terms of c
cosθ = c/√1+c²
Hence the formula for cos θ in terms of c is cosθ = c/√1+c²