The expression $$x^4- 2x^2 + k$$ will be a perfect square if the value of k is
It is clear that we have to write the expression in the form $$(a-b)^2$$.
The second term in the given expression in $$-2x^2$$. This expression must correspond to the form 2ab. Hence, $$a = x^2$$ and $$ b=1$$.
Hence, k must be equal to 1 for the expression to be a perfect square.
Option A is the right answer.
Create a FREE account and get:
Day-wise Structured & Planned Preparation Guide
By proceeding you agree to create your account
Free CAT Schedule PDF will be sent to your email address soon !!!
