Help please with a few quadratics
I have a few problems I have having difficulty at arriving at a solution that fits correctly.
The first one solve the equation:
5x^2 - x - 1 = 0
The second seems to be very difficult for me:
f (x) = -0.02x^2 + x + 1
moldels the yearly growth of a young redwood tree, f (x), in inches, with x inches of rainfall per year. How many inches of rainfall per year result in maximum tree growth? What is the yearly growth?
The Third Problem:
Solve equation by making an appropriate substitution. When necessary check proposed solutions.
x^-2 + x^-1 - 56 = 0
Express solution to equation in simplified form. Rationalize denominators. Solve equation by the square root property.
(x - 3)^2 = 20
Earboth or Hacker are you around?
A baseball player hits a pop fly into the air. The function
s(t) = - 16t^2 + 64t + 5
When does the baseball reach its maximum height? What is that height?
Okay I have tried several times to come up with this answer as in the book which is
The baseball will reach its maximum height of 69 feet after 2 seconds.
I am really confused once I turn the equation into the vertex.
Please help me. I know you both have different ways of doing them and I have tried both but I am completely missing something here?