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Tarul Jhalani
Subject: Maths
, asked on 20/3/18
Q15:
15.
A
=
cos
α
sin
α
-
sin
α
cos
α
t
h
e
n
P
r
o
v
e
t
h
a
t
A
a
=
cos
η
α
sin
η
α
-
sin
η
α
cos
η
α
w
h
e
r
e
η
i
s
a
p
o
s
i
t
i
v
e
i
n
t
e
g
e
r
.
Answer
1
Shubhrajyoti Ghosh
Subject: Maths
, asked on 19/3/18
Q. Solve the LPP by graphical method :
Maximize : Z = 5x + 3y
Subject to 3x+5y
≤
15
x+2y
≤
10
x,y
≥
0
Answer
1
Shubhrajyoti Ghosh
Subject: Maths
, asked on 19/3/18
No links please
(i) If
A
=
4
5
5
6
, show that, A
2
= 10A+I, where I is the units matrix of order 2.
Answer
1
N I S H I D H A .
Subject: Maths
, asked on 18/3/18
Please clear my doubt. :/
tan
θ
S
e
c
θ
tan
θ
tan
θ
-
s
e
c
θ
+
s
e
c
θ
-
tan
θ
-
s
e
c
θ
-
s
e
c
θ
tan
θ
S
o
l
tan
θ
s
e
c
θ
tan
2
θ
tan
2
θ
-
tan
θ
s
e
c
θ
+
-
tan
θ
s
e
c
θ
-
s
e
c
2
θ
-
s
e
c
2
θ
tan
θ
s
e
c
θ
=
0
tan
2
θ
-
s
e
c
2
θ
tan
2
θ
-
s
e
c
2
θ
0
I
s
tan
2
θ
-
s
e
c
2
θ
=
-
1
?
i
f
s
o
.
.
.
.
.
h
o
w
?
Answer
3
Shubhrajyoti Ghosh
Subject: Maths
, asked on 18/3/18
No links please:
(ii) Show that the matrix
A
=
1
3
1
2
2
2
1
-
2
-
2
2
-
1
is orthogonal.
Answer
1
Shubhrajyoti Ghosh
Subject: Maths
, asked on 17/3/18
No links please
Q3(ii). Using elementary row transformations find the inverse of the matrix
3
0
–
1
2
3
0
0
4
1
Ans :- 3b.(ii) A
–1
=
3
-
4
3
-
2
3
-
2
8
-
12
9
Answer
1
Tithi
Subject: Maths
, asked on 16/3/18
Solve this:
Q.18. If
A
=
1
π
sin
-
1
πx
tan
-
1
x
π
sin
-
1
x
π
c
o
t
-
1
πx
a
n
d
B
=
1
π
-
cos
-
1
πx
tan
-
1
x
π
sin
-
1
x
π
-
tan
-
1
πx
, then find the value of A - B.
Answer
1
Harshita Yadav
Subject: Maths
, asked on 15/3/18
value of cos x + sin y . tan z
Answer
1
Nithyashrri Saravanan
Subject: Maths
, asked on 14/3/18
Dear experts solve this is x=-14? Pl solve
3. Find x such that
1
x
1
1
3
2
2
5
1
15
3
2
1
2
x
=
0
Answer
1
Ritesh Ranjan Rath
Subject: Maths
, asked on 14/3/18
2) Find the distance between the planes
2
x
-
y
+
2
z
=
5
a
n
d
5
x
-
2
.
5
y
+
5
z
=
20
.
3
)
I
f
f
o
r
a
n
y
2
×
2
s
q
u
a
r
e
m
a
t
r
i
x
A
,
A
(
a
d
j
A
)
=
8
0
0
8
,
t
h
e
n
w
r
i
t
e
t
h
e
v
a
l
u
e
o
f
A
.
Answer
2
Shubhrajyoti Ghosh
Subject: Maths
, asked on 13/3/18
I
f
A
=
-
3
4
1
2
3
1
1
4
5
t
h
e
n
s
h
o
w
A
+
A
T
i
s
s
y
m
m
e
t
r
i
c
m
a
t
r
i
x
a
n
d
A
-
A
T
i
s
s
k
e
w
s
y
m
m
e
t
r
i
c
m
a
t
r
i
x
.
Answer
1
Shubhrajyoti Ghosh
Subject: Maths
, asked on 13/3/18
No links please 122
(
i
)
F
o
r
t
h
e
m
a
t
r
i
x
A
=
1
2
2
2
1
2
2
2
1
,
s
h
o
w
t
h
a
t
A
2
-
4
A
-
5
I
3
=
0
a
n
d
h
e
n
c
e
f
i
n
d
A
-
1
Answer
1
Shubhrajyoti Ghosh
Subject: Maths
, asked on 13/3/18
No links please
Q
.
I
f
A
=
1
2
-
3
2
3
2
3
-
3
-
4
t
h
e
n
f
i
n
d
A
-
1
a
n
d
h
e
n
c
e
s
o
l
v
e
t
h
e
f
o
l
l
o
w
i
n
g
e
q
u
a
t
i
o
n
s
:
x
+
2
y
-
3
z
=
-
4
2
x
+
3
y
+
2
z
=
2
3
x
-
3
y
-
4
z
=
11
(
2
)
(
b
)
o
r
,
X
=
3
;
Y
=
-
2
;
Z
=
1
Answer
1
Aditi Sharma
Subject: Maths
, asked on 23/2/18
S
o
l
v
e
t
h
i
s
:
x
2
+
1
x
y
x
z
x
y
y
2
+
1
y
z
z
x
z
y
z
2
+
1
=
1
+
x
2
+
y
2
+
z
2
Answer
1
Sudipan
Subject: Maths
, asked on 23/2/18
Q. Solve for x, y, z from these three equations
2
x
+
3
y
+
10
z
=
4
,
4
x
-
6
y
+
5
z
=
1
,
6
x
+
9
y
-
20
z
=
2
Answer
1
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What are you looking for?
15.
Q. Solve the LPP by graphical method :
Maximize : Z = 5x + 3y
Subject to 3x+5y 15
x+2y 10
x,y 0
(i) If , show that, A2 = 10A+I, where I is the units matrix of order 2.
(ii) Show that the matrix is orthogonal.
Q3(ii). Using elementary row transformations find the inverse of the matrix
Ans :- 3b.(ii) A–1 =
Q.18. If , then find the value of A - B.
3. Find x such that