Quadratic Equation (Check my Workings ?)

AI Thread Summary
The quadratic equation 3t^2 + 7t - 5 = 0 was solved using the quadratic formula. The calculations led to two potential solutions: t = -4.39 and t = -9.61. However, these results differ from the tutor's answer of t = 0.573 and t = -2.907. The error was identified as a miscalculation in the denominator, which should not equal 4. This highlights the importance of careful arithmetic in solving quadratic equations.
lloydowen
Messages
78
Reaction score
0

Homework Statement



Solve using the formula method.

Homework Equations



3t^2+7t=5

The Attempt at a Solution



3t^2+7t-5=0<br /> t= \frac{-7 +or-\sqrt{7^2-4(3)(-5)}}{2(3)}<br /> <br /> t= \frac{-7+\sqrt{109}}{4}<br /> t= -4.39<br /> OR...
t= \frac{-7-\sqrt{109}}{4}<br /> t= -9.61

The reason I have doubts is because the answer book from the tutor shows, T= 0.573 or -2.907... ? :(
 
Physics news on Phys.org
Ah ****, misuse of the formula tags, :( For some reason it won't let me go back and edit, hope you guys can understnad that :/
 
lloydowen said:
3t^2+7t-5=0<br /> t= \frac{-7 +or-\sqrt{7^2-4(3)(-5)}}{2(3)}<br /> <br /> t= \frac{-7+\sqrt{109}}{4}<br /> t= -4.39<br /> OR...
t= \frac{-7-\sqrt{109}}{4}<br /> t= -9.61

The reason I have doubts is because the answer book from the tutor shows, T= 0.573 or -2.907... ? :(
In the denominator, 2(3) does not equal 4.
 
Oh! Such a silly mistake, I feel like a fool now !
 
I picked up this problem from the Schaum's series book titled "College Mathematics" by Ayres/Schmidt. It is a solved problem in the book. But what surprised me was that the solution to this problem was given in one line without any explanation. I could, therefore, not understand how the given one-line solution was reached. The one-line solution in the book says: The equation is ##x \cos{\omega} +y \sin{\omega} - 5 = 0##, ##\omega## being the parameter. From my side, the only thing I could...
Back
Top