What is the formula for the magnetic field induction at any general point ‘p’ 

 Magnetic induction at point ‘p’ due to magnet  $N_1{ \mathrm{S}}_1$ of moment
 $M\cos \theta$     is   $B=\frac{{\mu }_0}{4\pi }\frac{M\cos \theta }{d^3}$---(1)  (Point lies on axial line)
Magnetic induction at point ‘p’ due to magnet  $N_1{ \mathrm{S}}_1$ of moment 
$M\cos \theta$        is  $B=\frac{{\mu }_0}{4\pi }\frac{M\cos \theta }{d^3}$ ------( 2 ) (Point lies on equatorial line)
These  two Magnetic inductions are perpendicular to each other. The resultant Magnetic  induction at p is given by 
                                       $B=\sqrt{B_1^2+{B_2}^2}=\frac{{\mu }_0}{4\pi }\frac{M}{d^3}\left(\sqrt{1+3{\cos }^2\theta }\right)$