Straight LineHard
Question
The graph of the function cos x cos (x + 2) - cos2 (x + 1) is
Options
A.a straight line passing through (0, - sin2 1) with slope 2
B.a straight line passing through (0, 0)
C.a parabola with vertex (1,-sin2 1)
D.a straight line passing through the point 
and parallel to the x-axis
and parallel to the x-axisSolution
Let y = cos x cos (x + 2) - cos2 (x - 1)
= cos (x + 1 - 1) cos(x + 1 - 1) - cos2 (x + 1)
= cos2 (x + 1) - sin2 1- cos2 (x + 1)
y = -sin2 1
This is a straight line which is parallel ro x-axis.
It passes throught (π / 2,- sin21)
= cos (x + 1 - 1) cos(x + 1 - 1) - cos2 (x + 1)
= cos2 (x + 1) - sin2 1- cos2 (x + 1)
y = -sin2 1
This is a straight line which is parallel ro x-axis.
It passes throught (π / 2,- sin21)
Create a free account to view solution
View Solution FreeMore Straight Line Questions
The acute angle between the lines y = 3 and y = √3 x + 9 is -...The x-coordinate of the incentre of the triangle that has the coordinates of mid points of its sides as (0, 1)(1, 1) and...The lines x + (a − 1) y + 1 = 0 and 2x + a2y − 1 = 0 are perpendicular if...If the coordinates of the points A, B, C be (−1, 5), (0, 0) and (2, 2) respectively and D be the middle point of B...Let the angles made with the positive x -axis by two straight lines drawn from the point $P(2,3)$ and meeting the line $...