Given this ffplay command, I am expecting that the sine wave goes from 440hz to 454.4hz over 10 seconds then continue playing at 454.4hz for another 10 seconds. Instead, the transition is at different frequencies making it not smooth. What am I doing wrong?

ffplay -f lavfi -i "
        aevalsrc='sin(2*PI*t*(440 + (14.4*t/10)))':s=44100:d=10[wave1];
        aevalsrc='sin(2*PI*t*454.4)':s=44100:d=10[wave2];
        [wave1]afade=t=in:st=0:d=5[wave1];
        [wave2]afade=t=out:st=5:d=5[wave2];
        [wave1][wave2] concat=n=2:v=0:a=1"