Q55 / 170 · Manipal (MET) 2018 · Mathematics
If $P(n): 1+3+5+\ldots+(2 n-1)=n^2$ is
- Correct answerAtrue for all $n \in N$
- Btrue for $n\gt1$
- Ctrue for no $n$
- DNone of these
Solution
Since, $P(1): 1=1$ (true)
$\begin{aligned}
& \text { Let } \quad P(k) \\
& \therefore 1+3+5+\ldots+(2 k-1)=k^2 \\
& \therefore P(k+1) \\
& \equiv 1+3+5+\ldots+(2 k-1)+2 k+1 \\
& \\
& \\
& =k^2+2 k+1=(k+1)^2
\end{aligned}$
So, it holds for all $n$.
So, it holds for all $n$.
Hence, the correct answer is option: 'A'.