CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
128
You visited us 128 times! Enjoying our articles? Unlock Full Access!
Question

Number of points where f(x)=[x]sin2(πx) is not differentiable if x(7,10) is (where [.] denotes the greatest integer function)

A
15
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
0
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
6
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
17
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 0
f(x)=[x]sin2(πx)
f(x)=⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪7sin2(πx),x(7,6)0,x=66sin2(πx),x(6,5)0,x=50,x=99sin2(πx),x(9,10)
Clearly f(x) is continuous for x(7,10)

f(x)=⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪7sin(2πx),x(7,6)0,x=66sin(2πx),x(6,5)0,x=50,x=99sin(2πx),x(9,10)
Clearly f(x) is differentiable for x(7,10)
Hence, there is no such point where f(x) is not differentiable for x(7,10)

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Right Hand Derivative
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon