Answer:
I think the answer is C.....
Answer:
x = 4 , y = 2
Step-by-step explanation:
Using the sine / tangent ratios in the right triangle and the exact values
sin60° =
and tan60° =
, then
sin60° =
=
=
( cross- multiply )
x
= 4
( divide both sides by
)
x = 4
and
tan60° =
=
=
( multiply both sides by y )
y
= 2
( divide both sides by
)
y = 2
You did it right (almost, I got 21 instead of 19) but didn't finish. You need to show your discriminant is never negative.
x² + (p+1)x = 5-2p
x² + (p+1)x +(2p-5) =0
Real roots mean a positive (or at least non-negative) discriminant:
D = b² - 4ac = (p+1)² - 4(1)(2p - 5) = p² + 2p + 1 - 8p + 20
D = p² - 6p + 21
It's not totally obvious that D>0; we prove that by completing the square by noting
(p-3)² = p² - 6p + 9
so
p² - 6p = (p-3)² - 9.
D = p² - 6p + 21
D = (p-3)² - 9 + 21
D = (p-3)² + 12
Now we clearly see D>0 always because the squared term can't be negative, so D is always at least 12. We always get two distinct real roots.
Answer:
(1,-3.7)
Step-by-step explanation:
subtract the y axis to go down
5 - 8.7 = -3.7