Mischa wrote the quadratic equation 0 = –x2 + 4x – 7 in standard form
The standard form of quadratic equation is
When y=0 then the standard equation becomes
Now we compare the given equation 
with and find the value of a, b,c
-x^2 can be written as -1x^2
a= -1 , b=4 and c=-7
The value of c is -7
Answer: option a.
Step-by-step explanation:
By definition, we know that:
Substitute 
into the first equation, solve for the cosine and simplify. Then, you obtain:
As 
then 
:
Now we can find 
:
Answer:
√10/2x
Step-by-step explanation:
Multiply by √6 on the top and bottom to rationalize the denominator.
(√15×√6)/(√6x×√6) = √90/6x = (√9×√10)/6x = 3√10/6x = √10/2x
