Answer:
a,b and c.
Step-by-step explanation:
We have to find the the functions that are their own inverses.
a.t(p)=p
Then the inverse function of given function is

Therefore, the given function is inverse function of itself.
Hence, option a is true.
b.y(j)=![-\frac{1}{j}Let y(j)=y then we get [tex]y=-\frac{1}{j}](https://tex.z-dn.net/?f=-%5Cfrac%7B1%7D%7Bj%7D%3C%2Fp%3E%3Cp%3ELet%20y%28j%29%3Dy%20then%20we%20get%20%3C%2Fp%3E%3Cp%3E%5Btex%5Dy%3D-%5Cfrac%7B1%7D%7Bj%7D)




Hence, the function is inverse of itself.Therefore, option b is true.
c.
Suppose that w(y)=w
Then 




Hence, the function is inverse function of itself.Therefore, option c is true.
d.
Let d(p)=d
If we replace ![\frac{1}{x^2}by p then we get [tex]d=\frac{1}{x^2}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bx%5E2%7Dby%20p%20then%20we%20get%20%3C%2Fp%3E%3Cp%3E%5Btex%5Dd%3D%5Cfrac%7B1%7D%7Bx%5E2%7D)



Hence, the function is not self inverse function.Therefore, option d is false.