Answer:
Part 1) 
Part 2) 
Part 3) 
Part 4) 
Step-by-step explanation:
step 1
Find the length side c
Applying the Pythagoras Theorem

substitute the given values



step 2
Fin the measure of angle B
we know that
In the right triangle

substitute the given values


step 3
Find the measure of angle A
we know that
The measure of interior angles in a triangle must be equal to 180 degrees
so
∠A+∠B+∠C=180°
Remember that in a right triangle the measure of angle C is 90 degrees
we have


substitute


The Answer is the first one
The answer to the missing value is X = 3
1 joule = 6,242e+18ev
20 joule = 20 joule *6,242e+18 ev/joule =1,248e+20 ev
1,248e+20 ev / (10 ev / photon) =1,248e+19 photons.
We know that
Any point <span>(x,y)</span> on the parabola is equidistant from the focus and the directrix
Therefore,
focus (0,4) and directrix of y=2
<span>√[<span>(x−0)</span></span>²+(y−4)²]=y−(2)
<span>√[x</span>²+(y-4)²]=y-2
x²+(y-4)²=(y-2)²
x²+y²-8y+16=y²-4y+4
x²=4y-12-----> 4y=x²+12----->y= (x²/4)+3
the answer is
y= (x²/4)+3