Question

2. The sum of digits of a two digit number is 13. If the number is subtracted from the
one obtained by interchanging the digits, the result is 45. What is the number?​

Answer 1

Answer:

Observe that

sin4θ+cos4θ=1−2sin2θcos2θ⟺sin4θ+cos4θ+2sin2θcos2θ=1

which is always true since

sin4θ+cos4θ+2sin2θcos2θ=(sin2θ+cos2θ)2=12=1

so the identity is proved.

Step-by-step explanation:

hope it will help you..

Answer 2

Let the number is 10x+y

so x+y=13__(1)

New number is  10y+x

∴10y+x−10x−y=45

⇒9(y−x)=45

⇒ y−x=5___(2)

From (1) & (2)

2y=18  y=9

so x=4

∴ the number is 49