In[]:=
f[x_]:=
h*Tan[x]^2
BL
+
Cot[x]^2
2CL
+
1
w*L*Sin[x]^2*Cos[x]^2
​​f'[x]
Out[]=
-
Cot[x]
2
Csc[x]
CL
-
2
3
Csc[x]
Sec[x]
Lw
+
2Csc[x]
3
Sec[x]
Lw
+
2h
2
Sec[x]
Tan[x]
BL
In[]:=
Solve-
Cot[x]
2
Csc[x]
CL
-
2
3
Csc[x]
Sec[x]
Lw
+
2Csc[x]
3
Sec[x]
Lw
+
2h
2
Sec[x]
Tan[x]
BL
==0,x
Out[]=
​