answer: 60
age difference is 30 years
10x4=40
40-10=30
when she is 30 he will be 60 because 30(her age) + 30 (age difference) = 60
Animal skins, animal bones, wood, and more. Depending on what era they were in.
csc(2x) = csc(x)/(2cos(x))
1/(sin(2x)) = csc(x)/(2cos(x))
1/(2*sin(x)*cos(x)) = csc(x)/(2cos(x))
(1/sin(x))*1/(2*cos(x)) = csc(x)/(2cos(x))
csc(x)*1/(2*cos(x)) = csc(x)/(2cos(x))
csc(x)/(2*cos(x)) = csc(x)/(2cos(x))
The identity is confirmed. Notice how I only altered the left hand side (LHS) keeping the right hand side (RHS) the same each time.
The answer is d=<span>= 1/2 (a+b) 2nd power </span>