Which of the following curves represents the function y = ln(|e^(|x| - pi)|) for |x| <= 2*pi? Here, x represents the abscissa and y represents the ordinate.
A. (curve showing V-shape touching zero at x = +/-pi with smooth symmetric profile)
B. (curve with two peaks and a sharp dip)
C. (curve with |x|-pi shape: V-shaped touching zero at +/-pi, linear rise on both sides)
D. (curve with inverted shape)
GATE 2016 · General Aptitude · Functions · medium
Answer: y = |x| - pi; the correct curve is option C (V-shaped, vertex at y = -pi, crossing zero at x = +/-pi).
Simplify the expression inside ln: The absolute value around the exponential is redundant. So y = ln(e^(|x|-pi)).
Apply ln(e^t) = t: The natural log undoes the exponential: y = |x| - pi. This is a V-shaped linear function.
Find key points and shape: The vertex is at (0, -pi approx -3.14). The graph crosses zero at x = +/-pi approx +/-3.14. On the domain [-2pi, 2pi] the graph is a symmetric V with slopes +1 (for x>0) and -1 (for x<0).