A
using the Cosine rule in ΔSTU
let t = SU, s = TU and u = ST, then
t² = u² + s² - (2us cos T )
substitute the appropriate values into the formula
t² = 5² + 9² - (2 × 5 × 9 × cos68° )
= 25 + 81 - 90cos68°
= 106 - 33.71 = 72.29
⇒ t =
≈ 8.5 in → A
Answer:
17/4
Step-by-step explanation:
add the fractions
Answer:
Part A)
x=-3i
x=3i
Part B)
(x+3i)(x-3i)
Step-by-step explanation:
Given:
Part A)
x^2+9=0
x^2=-9
x= √-9
x=√-1 *√9
x=± i *3
x=±3i
Part B)
x^2+9=0
x^2 - (-9)=0
x2-(3i)^2=0
(x-3i)(x+3i)=0 !