No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
x=2nπ
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
x=nπ+π/4
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
x=(2n+1)π+π/4
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution
The correct options are Bx=2nπ Dx=(2n+1)π+π/4 |cosx|=cosx−2sinx For cosx>0⇒(4n−1)π2<x<(4n+1)π2 cosx=cosx−2sinx⇒2sinx=0⇒sinx=0⇒x=nπ ∴x=2nπ And for cosx<0⇒(4n+1)π2<x<(4n+3)π2 −cosx=cosx−2sinx⇒−2cosx+2sinx=0⇒cosx+sinx=0 ⇒sin(π4+x)=0 ∴x=(2n+1)π+π4