Question

if x= 4cosA+5sinA and y=4sinA-5cosA then the value of X2+y2 is?​

Answer 1

Answer:

x²+y²=41

Step-by-step explanation:

x= 4cosA+5sinA

y= 4sinA-5cosA

x²+y²= (4cosA+5sinA)²+(4sinA-5cosA)²

=16cos²A+25sin²A+40cosAsinA+16sin²A+25cos²A-40cosAsinA

=41cos²A+41sin²A

=41(cos²A+Sin²A)

=41 (since, cos²A+sin²A=1)