 Hello and welcome to the session. Let us understand the following problem today. Prove that psi inverse 8 by 17 plus psi inverse 3 by 5 is equal to tau inverse 77 by 36. Now let us write the solution. First of all, let us write the formula that we will be using in the of a problem. Let us, psi inverse x plus minus psi inverse y is equal to psi inverse of x into under root 1 minus y square plus minus y into under root 1 minus x square. Now using this formula, we have x is equal to 8 by 17, y is equal to 3 by 5. Now putting in the formula, we get psi inverse 8 by 17 plus psi inverse 3 by 5 is equal to psi inverse of 8 by 17 into 1 minus 3 by 5 the whole square plus 3 by 5 into under root 1 minus 8 by 17 the whole square which is equal to psi inverse of 8 by 17 into 1 minus 9 by 25 plus 3 by 5 into 1 minus 64 by 289. We solve the number to get psi inverse of 8 by 17 into 4 by 5 plus 3 by 5 into 15 by 17 which is equal to psi inverse of 32 plus 45 by 85 which is equal to psi inverse of 77 by 85. Now, let psi inverse of 77 by 85 is equal to theta which implies psi theta is equal to 77 by 85 which is equal to nothing but perpendicular by hypotenuse. Therefore, by using Pythagoras theorem, the base of a right-angled triangle will be 36. Therefore, we know tan theta is equal to perpendicular by base which is equal to 77 by 36 which implies tan theta is equal to 77 by 36 which implies theta is equal to tan inverse of 77 by 36. Therefore, psi inverse of 8 by 17 plus psi inverse of 3 by 5 is equal to tan inverse of 77 by 36 hence proved. I hope you understood the problem. Bye and have a nice day.