Step-by-step explanation:
tan30° = Height of person / (Distance away from river bank + river's width) = 1/√3.
Therefore 1.6m / (2m + x) = 1/√3
By cross multiplication, 1.6√3 = 2 + x.
Hence, x ≈ 0.77m.
Answer:
x=πn, n∈Z
Step-by-step explanation:
if sin²2x=1-cos²2x, then
1-cos²2x-2cos2x+2=0; ⇒ cos²2x+2cos2x-3=0; ⇔ (cos2x+3)(cos2x-1)=0;

Answer:
2/3
Step-by-step explanation:
Given that:
Number of students = 80
Number of parents = 40
fraction of the ratio of students to the total number of people at the graduation
Total number of people at graduation =. (number of students + number of parents)
80 + 40 = 120
Number of students : total people
80 : 120
80/120 = 8/12 = 2/3
Answer:
All of them are true except the 5th from the top
Step-by-step explanation:
Answer:
tvu is half of angle twu.
tvu=twu/2
tvu=145°/2
tvu=72.5°