The Gateway to Computer Science Excellence
0 votes
26 views

The number of real roots of the equation $1+\cos ^2x+\cos ^3 x – \cos^4x=5$ is equal to

  1. $0$
  2. $1$
  3. $3$
  4. $4$
in Numerical Ability by Veteran (425k points)
recategorized by | 26 views
0
Is $4$ the answer??
0

@ankitgupta.1729

Any idea how this could be done??

+1

@`JEET

To make equation satisfy, $cos^2 x +cos^3 x - cos^4 x = 4$ but $-1 \leq cosx \leq +1$. Here, we can't make sum $= 4$ for any real value of $x$. So, no real $x$ exists.

+1
Thanks.

Please log in or register to answer this question.

Related questions

Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true
50,645 questions
56,596 answers
195,824 comments
102,078 users