Solve the following problem: X^4-7x^2-30=0
2 answers:
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Answer:
The depth of the reflector is 0.84 feet
Step-by-step explanation:
<em>(See the figure below)</em>
The equation of a parabola centered at the origin with an axis of symmetry on y-axis is:
(1)
With p the distance from the origin to the focus using p=6, the equation (1) of the parabola becomes:
(2)
Note that the point B is on the parabola, so this point should satisfy the parabola equation (2) that allow us to use the value x=4.5 to find the y value associated to it, that it is the depth (h) of the reflector:
, solving for y
Answer:
=
+
Step-by-step explanation:
To verify the identity:
sinx/1-cosx = cscx + cotx
we will follow the steps below;
We will take just the left-hand side and work it out to see if it is equal to the right-hand side
sinx/1-cosx
Multiply the numerator and denominator by 1 + cosx
That is;
=
open the parenthesis on the right-hand side of the equation at the numerator and the denominator
sinx(1+cosx) = sinx + sinx cosx
(1-cosx)(1+cosx) = 1 - cos²x
Hence
=
But 1- cos²x = sin²x
Hence we will replace 1- cos²x by sin²x
=
=
=
= +
= +
= +
=
+
Note that;
=
=