NEET-XII-Physics

01: Introduction to Physics

by HC Verma - page 2
  • #6
    ∫dx2ax-x2=ansin-1xa-1.
    The value of n is
    -(a) 0
    (b) -1
    (c) 1
    (d) none of these.
    You may use dimensional analysis to solve the problem.
    digAnsr:   a
    Ans : (a) 0
    [ax] = [x2]
    ⇒ [a] = [x] ...(1)
    Dimension of LHS = Dimension of RHS
    `` \Rightarrow \left[\frac{dx}{\sqrt{{x}^{2}}}\right]=\left[{a}^{n}\right]\phantom{\rule{0ex}{0ex}}\Rightarrow \left[\frac{L}{L}\right]=\left[{a}^{n}\right]...\left(2\right)\phantom{\rule{0ex}{0ex}}\left[{L}^{0}\right]=\left[{a}^{n}\right]\phantom{\rule{0ex}{0ex}}n=0\phantom{\rule{0ex}{0ex}}``