Question

Please help, my teacher refuses to explain how to do the math and I need this class to graduate.

-x^4+3x^2+2x+2


I need to find:
• Domain/Range
• Local Minimum/Maximum
• Intervals of Increase/Decrease
As x —> - ∞
As x —> ∞
Determine the x-intercepts
Determine the y-intercepts

I’m not sure what intervals of increase or decrease is, or what the “x —> ∞ stuff is either. I think all I can do is find the domain. Please help soon!

Answer 1

Domain- (−∞,∞),x∈R

Range- (−∞,17+6√3(over)4], {y∣y≤17+6√3(over)4}

Local Minimum/Maximum- (−1,2) is a local maxima

(1+√3(over)2 ,17+6√3(over)4) is a local maxima

(1−√3(over)2 ,17−6√3(over)4)is a local minima

Intervals of Increase/Decrease- Increasing on: (−∞,−1)(1−√3(over)2,1+√3(over)2)

Decreasing on: (−1,1−√3(over)2),(1+√3(over)2,∞)

Explanation:

i hope this helps !

Answer 2

• Domain: All real numbers

• Range: (-∞, ∞)

• To find the local minimum/maximum and intervals of increase/decrease, we need to take the first and second derivatives of the function:

First derivative: -4x^3 + 6x + 2

Setting this equal to zero and solving for x, we get critical points at x ≈ -1.23, x ≈ 0.65, and x ≈ 1.23.

Second derivative: -12x^2 + 6

• At x ≈ -1.23, the second derivative is negative, so we have a local maximum.

• At x ≈ 0.65, the second derivative is positive, so we have a local minimum.

• At x ≈ 1.23, the second derivative is negative, so we have a local maximum.

• As x —> -∞, the function approaches ∞.

• As x —> ∞, the function approaches ∞.

• To find the x-intercepts, we set the function equal to zero and solve for x:

-x^4+3x^2+2x+2 = 0

This is a quartic equation that can be solved using various methods, such as factoring or using the quadratic formula. One solution is x ≈ -1.38. The other three solutions are complex numbers.

• To find the y-intercept, we set x = 0:

-y^4 + 2 = 0

Solving for y, we get y ≈ ±1.19. So the y-intercepts are (0, 1.19) and (0, -1.19).