Question

x= r.cosAcosB,y=rcosA.sinB and Z=r.sinA then prove that x²+y²+z²=r²​

Answer 1

Answer:

cos²A + sin²A = 1

cos²B + sin²B = 1

Step-by-step explanation:

x = rcosAcosB

y = rcosAsinB

z = rsinA

x² + y² + z²

r²cos²Acos²B + r²cos²Asin²B + r²sin²A

r²cos²A(cos²B+sin²B) + r²sin²A

r²cos²A + r²sin²A

r²(cos²A + sin²A)

r²