Most Important Selected Qs for JEE AdvancedMathematicsDefinite Integration
If f(x)+g(x)+h(x)=2 x R , then the value of the expression ₀^ 3 / 4 (f^2(x)+g^2(x)+h^2(x) ) d x , can be:
Options
- A1 2
- B1
- C3 2
- D4
Correct answer
D. 4
Step-by-step solution
Let v ₁= i + j + k and v ₂=f(x) i +g(x) j +h(x) k Now, v ₁ v ₂=2= | v ₁ | | v ₂ | = 3 f^2(x)+g^2(x)+h^2(x) Hence, 4 3 ^2 =f^2(x)+g^2(x)+h^2(x) 4 3 Hence, I_ = ₀^ 3 / 4 (f^2(x)+g^2(x)+h^2(x) ) d x= ₀^ 3 / 4 4 3 d x=1