Question

find the value of sec 45 , cosec30 and cos60 geometrically.
pls fast its urgent

Answer 1

Answer:

cos (theta) is the ratio of base and hypotenuse in a right angled triangle say ∆ABC

Since in the right angled triangle one angle is 45° so other one will be 45° too. If length of base is a unit hence the length of perpendicular. so length of hypotenuse = a√2

so cos45°= a/a√2 =1/√2

sec45°= √2

Next incase of theta=30°

take an equilateral triangle say ∆PQR with each side of length a unit.

now draw a perpendicular from vertex Q to base PR to meet at M. so length of PM=MR=a/2 so length of QM = a√3/2

in this figure u can find ratio of sides similar to above for theta=30° or 60°