If x= 3 is one of quadratic equation 2x² px+ 30=0, find the value of p...
Given:Quadratic equation: 2x² + px - 30 = 0
Root: x = 3
Step 1: Substitute the given root into the quadratic equation
Substituting x = 3 into the equation, we get:
2(3)² + p(3) - 30 = 0
Simplifying the equation:
18 + 3p - 30 = 0
3p - 12 = 0
3p = 12
p = 4
Therefore, the value of p is 4.
Step 2: Find the other root of the quadratic equation
To find the other root, we can use the quadratic formula:
The quadratic formula states that for a quadratic equation of the form ax² + bx + c = 0, the roots are given by:
x = (-b ± √(b² - 4ac)) / 2a
In our case, the quadratic equation is:
2x² + px - 30 = 0
Comparing this with the general quadratic equation form, we have:
a = 2
b = p
c = -30
Substituting these values into the quadratic formula, we get:
x = (-p ± √(p² - 4(2)(-30))) / (2(2))
Simplifying further:
x = (-p ± √(p² + 240)) / 4
Since we already know one root is x = 3, we can substitute x = 3 into the equation and solve for p:
3 = (-p ± √(p² + 240)) / 4
Multiplying both sides by 4:
12 = -p ± √(p² + 240)
Squaring both sides:
144 = p² + 240
Rearranging the equation:
p² = 144 - 240
p² = -96
Since the value of p² is negative, this means that there is no real value of p that satisfies the equation. Hence, there is no other real root for the quadratic equation 2x² + px - 30 = 0.