find the maximum value of 2sin theta+3
Answers
Answer:
Calculate the value of maxima and minima of given question-
y(max)=2sin
2
θ−3sinθ+2
Differentiate both side w.r.t
dx
dy
=4sinθcosθ−3sinθ
Hence-
dθ
dy
=0
4sinθcosθ−3cosθ=0
Take common cosθ we get:
cosθ(4sinθ−3)=0
Now we get
cosθ=0
θ=90
∘
(4sinθ−3)=0
sinθ=
4
3
θ=48.59
Again, differentiating
dθ
dy
, we get
dθ
2
d
2
y
=4(cos
θ
−sin
2
θ)+3sinθ
Evaluate the value of maxima and minima after putting the value of θ=90
∘
, we get:
Case 1:-
θ=90
∘
=4cos180
0
+3sin90
∘
dθ
2
d
2
y
<−1
Y is max. Value when θ=90
∘
Case 2:-
θ=48.59
∘
=4cos97.18
0
+3sin48.59
∘
dθ
2
d
2
y
>0
Y is minimum value when θ=48.59
∘
θ=48.59
∘
So putting the value of θ=90
∘
y(max)=2sin
2
(−90)
∘
−3sin(−90)
∘
+2
=2+3+2
=7
Putting the value [θ=48.59
∘
]
y(min)=2sin
2
48.59
∘
−3sin48.59
∘
+2
=7/8
Hence, there is an answer..