45cos(x^2/18)

Solution for 45cos(x^2/18) equation:

x in (-oo:+oo)

45*cos((x^2)/18) = 0

cos((x^2)/18) = 0

cos((x^2)/18) = 0  <=>  (x^2)/18 = pi*k_1+pi/2 i k_1 należy do I

t_1 = pi*k_1+pi/2

(x^2)/18-t_1 = 0

1/18*x^2 = t_1 // : 1/18

x^2 = 18*t_1

x^2 = 18*t_1 // ^ 1/2

abs(x) = 3*2^(1/2)*t_1^(1/2)

x = 3*2^(1/2)*t_1^(1/2) or x = -(3*2^(1/2)*t_1^(1/2))

x = 3*2^(1/2)*pi*k_1+pi/2^(1/2) i k_1 należy do I

x = -3*2^(1/2)*pi*k_1+pi/2^(1/2) i k_1 należy do I

45*cos((x^2)/18) = 0  <=>  45 = 0 or 45*cos((x^2)/18) = 0  <=>  cos((x^2)/18) = 0

x in { 3*2^(1/2)*pi*k_1+pi/2^(1/2), -3*2^(1/2)*pi*k_1+pi/2^(1/2) }