Let f(x) = x^4 -4x^2 +3x find f(-3) a.-54 b.36 c.-126 d.108

b. 36

Step-by-step explanation:

Evaluate x^4 - 4 x^2 + 3 x where x = -3:

x^4 - 4 x^2 + 3 x = (-3)^4 - 4×(-3)^2 - 3×3

Hint: | Evaluate (-3)^2.

(-3)^2 = 9:

(-3)^4 - 49 - 3×3

Hint: | Determine the sign of (-3)^4.

(-3)^4 = (-1)^4×3^4 = 1×3^4:

3^4 - 4×9 - 3×3

Hint: | Compute 3^4 by repeated squaring.

3^4 = (3^2)^2:

(3^2)^2 - 4×9 - 3×3

Hint: | Evaluate 3^2.

3^2 = 9:

9^2 - 4×9 - 3×3

Hint: | Evaluate 9^2.

9^2 = 81:

81 - 4×9 - 3×3

Hint: | Multiply -4 and 9 together.

-4×9 = -36:

81 + -36 - 3×3

Hint: | Multiply 3 and -3 together.

3 (-3) = -9:

81 - 36 + -9

Hint: | Group the negative terms in 81 - 36 - 9 together and factor out the minus sign.

81 - 36 - 9 = 81 - (36 + 9):

81 - (36 + 9)

Hint: | Evaluate 36 + 9 using long addition.

| 1 |  

| 3 | 6

+ | | 9

| 4 | 5:

81 - 45

Hint: | Subtract 45 from 81.

| 7 | 11

| 8 | 1

- | 4 | 5

| 3 | 6:

36

step-by-step explanation:

answers available in this download

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2nd one in the first row is correct