JEE MainMathematicsTrigonometric Equations
The number of real solutions of the equation | x| = 1 - x 4 in the interval [0, 4 ] is
Options
- A7
- B4
- C9
- D8
Correct answer
D. 8
Step-by-step solution
The given equation is | x| = 1 - x 4 . Let f(x) = | x| and g(x) = 1 - x 4 . We need to find the number of points of intersection of these two graphs in the interval [0, 4 ] . The graph of f(x) = | x| consists of 4 positive arches of a sine wave in the interval [0, 4 ] , each of width and maximum height 1 . The graph of g(x) = 1 - x 4 is a straight line passing through (0, 1) and (4 , 0) . Let us analyze the intersections in each interval of length : 1. In [0, ] : g(x) decreases from 1 to 0.75 . The maximum of f(x)