Question

f ( x ) = 3x Square + 5 then find f ( y - 1 )​

Answer 1

Solution -

We have,

• f(x) = 3x² + 5

⠀

We have to find f(y - 1).

• Put x = y - 1

➝ f(y - 1) = 3(y - 1)² + 5

⠀

Using identity

• (a - b)² = a² + b² - 2ab

⠀

➝ f(y - 1) = 3(y² + 1 - 2y) + 5

➝ f(y - 1) = 3y² + 3 - 6y + 5

➝ f(y - 1) = 3y² - 6y + 3 + 5

➝ f(y - 1) = 3y² - 6y + 8

⠀

Hence,

• f(y - 1) = 3y² - 6y + 8

━━━━━━━━━━━━━━━━━━━━━━