Why is math.js returning the wrong number??

At math.js.org I have verified that the expression below will return the number -4.15, but when I run it in my app, it returns the number -61.6. I can’t figure it out!!

20*log10(sqrt((((1) cos(0.1pi/180)+(1)cos(-216pi/180))^2)+(((1*sin(0.1

*pi/180))+(1*sin(-216*pi/180)))^2)))