Answer:
see explanation
Step-by-step explanation:
let pq = x
given oq - pq = 1 then oq = 1 + x
Using Pythagoras' identity, then
(oq)² = 7² + x²
(1 + x)² = 49 + x² ( expand left side )
1 + 2x + x² = 49 + x² ( subtract 1 from both sides )
2x + x² = 48 + x² ( subtract x² from both sides )
2x = 48 ( divide both sides by 2 )
x = 24 ⇒ pq = 24
and oq = 1 + x = 1 + 24 = 25 ← hypotenuse
sinq =
= 
cosq =
= 
<h3>
Answer: Choice D. 4x^2 + 20x + 25</h3>
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Explanation:
Perfect square trinomials are in the form (a+b)^2 = a^2+2ab+b^2
So the first and last terms must be perfect squares. The middle term is twice that of the square roots of each first and last term.
Choice D fits the description because 4x^2 = (2x)^2 is the first term, so a = 2x and 25 = 5^2 is the last term meaning b = 5. Note how 2ab = 2*2x*5 = 20x is the middle term.
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(a+b)^2 = a^2+2ab+b^2
(2x+5)^2 = (2x)^2+2*2x*5+5^2
(2x+5)^2 = 4x^2 + 20x + 25
49
3+4 is 7
and squared is 2
7x7=49