In Mathematics 9, video lessons for the first to fourth quarter cover a wide range of topics to support students' learning. These video lessons are designed to provide visual and interactive explanations of mathematical concepts, making the learning process more engaging and accessible. The topics covered in the video lessons include solving quadratic equations, exploring quadratic functions, trigonometric functions, exponential and logarithmic functions, and more. Students can access these video lessons through various online platforms such as YouTube and other educational resources. The video lessons aim to reinforce classroom learning, provide additional explanations, and offer opportunities for self-paced study and review, ultimately supporting students in their mathematical journey throughout the academic year.