The purpose of this investigation was to explore the effects of stereotype threat on women's construction of gender and mathematical identities, and to examine how these various cognitive negotiations may affect their mathematical reasoning on challenging definite integral applications. This was a qualitative study that primarily utilized the episodic narrative interview method. A sample of 20 Calculus II students were given a calculus assessment and a survey regarding the importance of gender and mathematics to their identities. Results of the surveys were used to identify a purposeful sample of four participants to be interviewed. Analysis of the interview transcripts revealed four themes that offer some insight into women's experiences at the intersection of gender, mathematics, and stereotype threat. The findings include evidence that both gender identification and domain identification (the strength with which one identifies with mathematics) influence the effects of stereotype threat. More specifically, women, whose gender is more central to their identity and who care the most about their identities as mathematicians appear to be more vulnerable to the effects of stereotype threat. Findings also support earlier claims that gendered discourse in mathematics harms women's construction of mathematical identities. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]