13. If f(x) = ax*4 - bx*2+x+5 and f(-3)= 2, then f (3) is
a) -5
b) -2
c)-8
d) 8
Answers
Answer:
8
Step-by-step explanation:
⇒ f(-3) = a(-3)⁴ - b(-3)² + (-3) + 5
⇒ 2 = 81a - 9b - 3 + 5
⇒ 2 = 81a - 9b + 2
⇒ 0 = 81a - 9b ...(1)
f(3) = a(3)⁴ - b(3)² + 3 + 5
= 81a - 9b + 8
= 0 + 8 { from (1)}
= 8
Answer:
d) 8
Step-by-step explanation:
Given that, f(x) = ax*4 - bx*2+x+5 and f(-3)= 2.
We have to find the value of f(3).
Substitute value of x = -3 in ax⁴ - bx² + x + 5.
→ f(-3) = a(-3)⁴ - b(-3)² + (-3) + 5
→ 2 = 81a - 9b - 3 + 5
→ 2 = 81a - 9b + 2
→ 2 - 2 = 81a - 9b
→ 0 = 81a - 9b ...............(1)
As we have to find the value of f(3). This time, substitute value of x as 3.
→ f(3) = a(3)⁴ - b(3)² + 3 + 5
→ f(3) = 81a - 9b + 8 ..............(2)
Substitute value of (1) in (2)
→ f(3) = 0 + 8
→ f(3) = 8
Hence, the value of f(3) is 8.