Odpowiedź:
zad 1
a = ?
b = 5
c = 13
a = √(c² - b²) = √(13² - 5²) = √(169 - 25) = √144 = 12 [j]
[j] - znaczy właściwa jednostka
sinα =a/c = 12/13
cosα = b/c = 5/13
tgα = a/b = 12/5 = 2 2/5 = 2,4
ctgα = b/a = 5/12
zad 2
a₁ = 4
a₅ = a₁ + 4r = 16
a₁ + 4r = 16
4 + 4r = 16
4r = 16 - 4 = 12
r = 12/4 = 3
zad 3
P = (5 , 6 ) , K = ( - 2 , 5 )
xp = 5 , xk = - 2 , yp =6 , yk = 5
IPKI = √[(xk - xp)² + (yk - yp)²] = √[(- 2 - 5)² + ( 5 - 6)²] = √[(- 7)² + (- 1)²] =
= √(49 + 1) = √50 = √(25 * 2) = 5√2