Answer:
The answer is "[tex]39.01^{\circ}[/tex]"
Step-by-step explanation:
[tex]\to R= 828\\\\\to F_1= 401\\\\\to F_2=477\\\\\to \bold{R=\sqrt{F_1^2+F_2^2+2F_1F_2 \cos \theta}}[/tex]
[tex]828=\sqrt{401^2+477^2+2 \times 401 \times 477 \cos \theta}\\\\828=\sqrt{160801+227529+382554 \cos \theta}\\\\828=\sqrt{388330+382554 \cos \theta}\\\\[/tex]
square the above equation:
[tex](828)^2=(\sqrt{388330+382554 \cos \theta})^2\\\\[/tex]
[tex]685584 =388330+382554 \cos \theta\\\\685584 -388330=382554 \cos \theta\\\\297254=382554 \cos \theta\\\\\cos \theta=\frac{297254}{382554}\\\\\cos \theta=0.777025\\\\\theta= \cos^{-1} 0.777025\\\\\theta= 39.01^{\circ}[/tex]
