If (secA−tanA)
2
=x, then the value of x is:

Let's simplify the expression (secA−tanA)
2
:

x=(
cosA
1
​
−
cosA
sinA
​
)
2

x=(
cosA
1−sinA
​
)
2

x=
cos
2
A
(1−sinA)
2

​

Using the identity cos
2
A=1−sin
2
A:

x=
1−sin
2
A
(1−sinA)
2

​

x=
(1−sinA)(1+sinA)
(1−sinA)(1−sinA)
​

x=
1+sinA
1−sinA
​