A lack of student motivation in a higher-level high school mathematics class prompted the question: how does a teacher's belief in their ability to effectively teach content positively or negatively impact student motivation? The purpose of this phenomenological research study is to understand how teachers evaluate their self-efficacy and how that knowledge factors into classroom outcomes. The study further explores how teachers perceive their self-efficacy can impact student motivation for learning mathematics. It is through this comprehensive understanding of factors which drive student motivation that educators are able to design instructional teaching strategies to meet the needs of a variety of students in their classes. Findings derived from this study will further inform pre-service education, professional development curriculum, and shape the feedback loop between teachers, administrators, and colleagues. All of which may impact future generations of students. The ability to successfully motivate classroom students to learn mathematical content and to possess a full awareness of their self-efficacy will enable teachers to impact future generations of learners. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]