**Refer to question posted on blog of Mar 13 2018, **reproduced here for your convenience. Compare your solution with the one given here:

**Question:**

Show that the following expression: remains constant in the interval . Find this constant value.

**Solution/proof:**

Let y equal the given expression for x in the prescribed interval. Then, taking cube of both sides, we write

The only real value of , a constant. The roots of the quadratic equation for are complex. It is easy to check that for both and 1.

**Alternately, **derive the square roots of the expression within the radical; you can use the method of undetermined coefficients for this.

*Cheers,*

Nalin Pithwa.

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