I am writing code in opengl using C++ in Visual Studio. I have done all the include directories correctly (including glfw include and glfw libraries in the properties), and lib directories correctly but I am getting this error
1.Severity Code Description Project File Line Suppression State Error LNK2019 unresolved external symbol __imp__glViewport@16 referenced in function _main timeinput2 C:\Users\user\source\repos\timeinput2\Source.obj 1
2.Severity Code Description Project File Line Suppression State Error LNK2019 unresolved external symbol __imp__glOrtho@48 referenced in function _main timeinput2 C:\Users\user\source\repos\timeinput2\Source.obj 1
3.Severity Code Description Project File Line Suppression State Error LNK2019 unresolved external symbol __imp__glMatrixMode@4 referenced in function _main timeinput2 C:\Users\user\source\repos\timeinput2\Source.obj 1
4.Severity Code Description Project File Line Suppression State Error LNK2019 unresolved external symbol __imp__glLoadIdentity@0 referenced in function _main timeinput2 C:\Users\user\source\repos\timeinput2\Source.obj 1
5.Severity Code Description Project File Line Suppression State Error LNK2019 unresolved external symbol __imp__glClear@4 referenced in function _main timeinput2 C:\Users\user\source\repos\timeinput2\Source.obj 1
Why?