A 3.00 kHz tone is being produced by a speaker with a diameter of 0.175 m. The air temperature changes from 0 to 29°C. Assuming air to be an ideal gas, find the change in the diffraction angle

My solution

v directly proportional to sqrt T

v = sqrt 302 =17.382

lambda = v/f = 17.382/3000
=0.005794

Sin theta = 1.22 lambda/ diameter

= 1.22x 0.005794/0.175
=0.009425
theta = Sin^-1 0.009425
= 0.54

answer is wrong

First, v is prop to sqrt T does NOT mean that v=sqrt(Temp). That is plain wrong. So lambda that follows is wrong, and the angle also.

http://www.sengpielaudio.com/calculator-speedsound.htm

I used the calculator but stll got the wrong answer. PLease show work