Question

if cosA =4/5 then find sinA​

Answer 1

Answer:

sinA=3/5

Step-by-step explanation:

yiu can find it from pythagorean triplets(3,4,5) and sine firmula

Answer 2

Answer:

3/5

Step-by-step explanation:

we know that cos theta= base/hypotenuse

now given cosA=4/5

let us assume a right angled triangle where base is 4x units and hypotenuse is 5x units, because by doing this we are getting cosA=4/5

now if we apply Pythagoras theorem in that right angled triangle, then length of perpendicular=√(hypotenuse)^2- (base)^2

perpendicular=√(5x)^2-(4x)^2

perpendicular=√9x^2

perpendicular becomes 3x units

therefore sinA= perpendicular/ hypotenuse

sinA becomes 3x/5x or 3/5