If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

We are given that:

Now we are asked to show that:

We know that:

Hence using equation (1) we get:

Also we know that:

and

so using above two formula in equation (2) we get:

( since we know that:

)

Hence we have proved that:

the graph on the bottom right

  answer:

  write 548 as 500 + 40 + 8. multiply each addend by 5. then add the three products to get 2,740.