13. If [tex]$p(x)=x+3$[/tex], then [tex]$p(x)+p(-x)$[/tex] is equal to:

a) 3
b) [tex][tex]$2x$[/tex][/tex]
c) 0
d) 6

14. One of the zeroes of the polynomial [tex]$2x^2+7x-4$[/tex] is:

a) 2
b) [tex]$\frac{1}{2}$[/tex]
c) [tex][tex]$-\frac{1}{2}$[/tex][/tex]
d) -2



Answer :

Sure, let's solve these questions step-by-step:

### Question 13:
We need to find [tex]\( p(x) + p(-x) \)[/tex] where [tex]\( p(x) = x + 3 \)[/tex].

1. Calculate [tex]\( p(x) \)[/tex]:
Given [tex]\( p(x) = x + 3 \)[/tex],
[tex]\[ p(x) = x + 3 \][/tex]

2. Calculate [tex]\( p(-x) \)[/tex]:
Substitute [tex]\(-x\)[/tex] into the function [tex]\( p(x) \)[/tex]:
[tex]\[ p(-x) = -x + 3 \][/tex]

3. Add [tex]\( p(x) \)[/tex] and [tex]\( p(-x) \)[/tex]:
[tex]\[ p(x) + p(-x) = (x + 3) + (-x + 3) = x - x + 3 + 3 = 6 \][/tex]

Therefore, [tex]\( p(x) + p(-x) \)[/tex] is equal to [tex]\( 6 \)[/tex].

Answer: d) 6

### Question 14:
We need to determine one of the zeroes of the polynomial [tex]\( 2x^2 + 7x - 4 \)[/tex].

1. Identify the polynomial:
The polynomial is [tex]\( 2x^2 + 7x - 4 \)[/tex].

2. Find the roots of the polynomial:
To find the roots, we solve the equation [tex]\( 2x^2 + 7x - 4 = 0 \)[/tex].

The roots of a quadratic equation [tex]\( ax^2 + bx + c = 0 \)[/tex] are found using the quadratic formula:
[tex]\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]
where [tex]\( a = 2 \)[/tex], [tex]\( b = 7 \)[/tex], [tex]\( c = -4 \)[/tex].

3. Calculate the discriminant:
[tex]\[ \text{Discriminant} = b^2 - 4ac = 7^2 - 4 \cdot 2 \cdot (-4) = 49 + 32 = 81 \][/tex]

4. Calculate the roots:
[tex]\[ x = \frac{-7 \pm \sqrt{81}}{2 \cdot 2} = \frac{-7 \pm 9}{4} \][/tex]

- For [tex]\( + \sqrt{81} \)[/tex]:
[tex]\[ x = \frac{-7 + 9}{4} = \frac{2}{4} = \frac{1}{2} \][/tex]

- For [tex]\( - \sqrt{81} \)[/tex]:
[tex]\[ x = \frac{-7 - 9}{4} = \frac{-16}{4} = -4 \][/tex]

Thus, the roots of the polynomial [tex]\( 2x^2 + 7x - 4 \)[/tex] are [tex]\( \frac{1}{2} \)[/tex] and [tex]\( -4 \)[/tex].

One of the zeroes is [tex]\( \frac{1}{2} \)[/tex].

Answer: b) [tex]\(\frac{1}{2}\)[/tex]