\\
y(x_0)=y_0;\ \ y'(x_0)=y'_0;\\
y-y_0=y'_0(x-x_0)<==>y=kx+b;\\
y=y'_0\cdot x+y_0-y'_0\cdot x_0=kx+b;\\
y_0-y'_0\cdot x_0=b;\\
y'_0x=kx;\\
k=y'_0;\\
y'_0=y'(x_0);\\
y'(x)=-3\cdot\cos2x\cdot2+5\cdot(-\sin3x)\cdot3-0=\\
=-6\cos2x-15\sin2x;\\
k=y'_0=y'(x_0)=y'(\frac\pi2)=-6\cos(2\cdot\frac\pi2)-15\sin(2\cdot\frac\pi2)=\\
=-6\cos\pi-15\sin\pi=-6\cdot(-1)-15\cdot0=6-0=6;\\
k=6" alt="y=-3\sin2x+5\cos3x-7;\\
x_0=\frac\pi2\\
k-?\\
y-y(x_0)=y'(x_0)(x-x_0)==>\\
y(x_0)=y_0;\ \ y'(x_0)=y'_0;\\
y-y_0=y'_0(x-x_0)<==>y=kx+b;\\
y=y'_0\cdot x+y_0-y'_0\cdot x_0=kx+b;\\
y_0-y'_0\cdot x_0=b;\\
y'_0x=kx;\\
k=y'_0;\\
y'_0=y'(x_0);\\
y'(x)=-3\cdot\cos2x\cdot2+5\cdot(-\sin3x)\cdot3-0=\\
=-6\cos2x-15\sin2x;\\
k=y'_0=y'(x_0)=y'(\frac\pi2)=-6\cos(2\cdot\frac\pi2)-15\sin(2\cdot\frac\pi2)=\\
=-6\cos\pi-15\sin\pi=-6\cdot(-1)-15\cdot0=6-0=6;\\
k=6" align="absmiddle" class="latex-formula">